Method for tagging petroleum products

ABSTRACT

This invention provides a method for imparting invisible markings for identification purposes to petroleum hydrocarbons by incorporating one or more infrared fluorescing compounds therein. Certain infrared fluorophores from the classes of squaraines (derived from squaric acid), phthalocyanines and naphthalocyanines are useful in providing invisibly marked petroleum hydrocarbons such as crude oil, lubricating oils, waxes, gas oil (furnace oil), diesel oil, kerosene and in particular gasoline. The near infrared fluorophores are added to the hydrocarbons at extremely low levels and are detected by exposing the marked hydrocarbon compositions to near infrared radiation having a wavelength in the 670-850 nm range and then detecting the emitted fluorescent light via near infrared light detection means.

FIELD OF THE INVENTION

This invention belongs to the field of organic chemistry. In particular,this invention relates to a method for invisibly marking or taggingpetroleum products for identification purposes.

BACKGROUND OF THE INVENTION

It is known that the various petroleum hydrocarbons can be marked usingcolorants. However, there exists a need for invisibly markingpetroleum-derived products in order to identify the various grades offuels, to distinguish manufacturer's brands, and to make misuseimpossible or at least traceable. In this regard, it is desirable thatthe added marker be readily detected by non-scientific personnel.Finally, the marker should be detectable at low enough levels so thatthe physical and chemical properties of the petroleum product are notappreciably altered. Historically, various problems have accompanied theuse of dyes or colorants as markers for petroleum products, includingsludging, crystallization, or agglomeration of the dye upon standing orstorage.

U.S. Pat. Nos. 2,028,637; 2,925,333; 3,004,821; 3,164,449; 3,350,384;3,435,054; 3,690,809; 3,704,106; 4,009,008; 4,049,393; 4,303,407; and4,735,631; European Application No. 95 975; and U.S.S.R. Patent No.297,659 describe the use of colorants and dyes in marking petroleumproducts.

Ger. Offen. 1,913,912; and U.S. Pat. Nos. 4,278,444, 4,992,204; and5,279,967 describe visible or ultraviolet fluorescing compounds usefulas markers in petroleum products. The marking or tagging systems basedon UV fluorescence have the inherent disadvantage that many of thepetroleum hydrocarbons themselves contain condensed aromatic compoundswhich fluoresce when exposed to UV radiation.

U.S. Pat. No. 5,201,921 describes a method for marking plastic with UVfluorescent compounds.

U.S. Pat. No. 4,540,595 teaches the marking of documents such as bankchecks with certain fluorescent phenoxazine dyes.

U.S. Pat. No. 5,093,147 describes the use of polymethine infraredfluorescent compounds in bar codes.

U.S. Pat. No. 3,630,941 describes 16,17-dialkoxy-violanthrones vat dyesfor use as infrared fluorescers for marking articles.

All of the above infrared fluorophores lack adequate solubility in mostpetroleum hydrocarbons to be suitable for such use.

This invention provides a method for marking or tagging variouspetroleum products, for identification purposes. Preferably, the markersof the present invention are squaraines, phthalocyanines, ornaphthalocyanines which fluoresce in the near infrared region whenexposed to near infrared light. Also provided are certain near infraredfluorophoric compounds which are soluble in petroleum hydrocarbons.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an apparatus useful for practicing the present inventionfor identification of the near infrared (NIR) marker in the petroleumproducts as described herein. This arrangement will be understood to bean application of commercially available fluorometers. As may be seenfrom FIG. 1, there is present a light source (1) capable of emittingradiation in the visible and NIR region which illuminates the nearinfrared fluorophore-marked sample (2) through a wavelength selector (3)e.g., monochromator or interference filter. A wavelength selector (4)and a NIR sensitive photodetector (5) is placed at 90° or less angle. Itmay be seen from FIG. 1 that light source (1), wavelength selector (3 &4) and photodetector (5) are all arranged on two sides of a triangle tominimize scattered light entering the detector. The light source (1) inFIG. 1 may be replaced with lasers, preferably semiconductor lasers. Theoutput of photodetector (5) is provided to level adjustment amplifier(6), the output of which is provided to an integrated circuit digitalmultimeter (7). The output of the digital multimeter is connected to acomputer display so as to provide a numeral and graphical indication ofthe amount of luminous flux at the predetermined wavelength (preferablyat the emission maxima) emitted by the substance contained in sample.

FIG. 2 shows a preferred apparatus useful for practice of the presentinvention which will be understood to be a specialized arrangement forperforming the tests of the present invention. As may be seen from FIG.2, there is present a laser diode light source (1) capable of emittingradiation in the NIR region which is collimated through a collimatinglens (2), and illuminates the sample (4) through an optical filter (3).A focusing lens (5) and a beam compressor are placed at 30 degrees orless angle. It may be seen from FIG. 2 that the laser diode light sourceand the collimating lens are arranged to minimize scattered light fromentering the detector. An optical filter (6) is placed between thecompressor lenses (7 & 8) to select the wavelength of fluorescence ofthe tagging molecule which is focused on the photodetector. Acurrent-to-voltage converter is connected to the photodetector (9) toamplify the detector signal. The arrangement and the electroniccircuitry of the current-to-voltage amplifying (10) is widely known andthe routines of amplifying and processing the photodetector signal arealso well-known. The signal from the current-to-voltage convertercircuit is detected by a threshold detector (11). The threshold level ofthe threshold detector is set at the level required to minimize anyinterference from unmarked samples. The presence of tagged samples infront of the preferred apparatus is indicated by the light-emittingdiode (LED) indicator (12).

FIGS. 1 and 2 are more fully described below.

SUMMARY OF THE INVENTION

The present invention provides a method for tagging, for identificationpurposes, a petroleum product which comprises dissolving in said producta near infrared fluorophoric compound.

As a further aspect of the invention there is provided a petroleumproduct having dissolved therein at least one near infrared fluorophoriccompound.

As a further aspect of the invention, there is provided a method foridentifying a petroleum product, wherein said product has one or morenear infrared fluorophoric compounds dissolved therein, which comprisesthe steps:

(a) exposure of a petroleum hydrocarbon composition to electromagneticradiation having wavelengths of 670-850 nm, wherein said petroleumhydrocarbon composition comprises a petroleum hydrocarbon materialhaving dissolved therein one or more near infrared fluorescent taggingcompounds, wherein said tagging compound(s) is (are) present in aconcentration sufficient to impart detectable fluorescence when exposedto electromagnetic radiation of about 670-850 nm provided by lightsources; followed by

(b) detection of the emitted fluorescent radiation by near infrareddetection means.

DETAILED DESCRIPTION OF THE INVENTION

In the practice of the present invention, it is possible to mark, forexample, one grade of gasoline with one near infrared flurophoriccompound and another grade with a near infrared fluorophoric markerwhich fluoresces at a detectably different wavelength. In this fashion,the identity of a certain grade of gasoline can be confirmed withoutresorting to chemical analysis.

Ideally, the near infrared fluorophores useful in the practice of theinvention should possess the following properties:

1. adequate solubility in petroleum hydrocarbons to allow easydissolution to give concentrations of infrared fluorophore detectable byavailable infrared detectors;

2. strong absorbance of infrared light in the 670-850 nm wavelengthrange;

3. little or no absorbance in the 400 to about 670 nm range (visible),to permit essentially "invisible" markings;

4. strong infrared fluorescence when irradiated with infrared radiantshaving wavelengths of about 670-850 nm;

5. give detectable emission levels when added to petroleum hydrocarbonsat extremely low levels, e.g. 1 ppm or less.

6. have adequate stability, e.g. to sunlight, water, oxygenates,temperature, etc.

7. be environmentally safe.

It is also within the scope of the invention to mark one or morepetroleum hydrocarbons with two or more infrared fluorophores, saidfluorescing compounds having been selected so that they absorb infraredand/or reemit fluorescent light at wavelengths different enough fromeach other as not to interfere with individual detection.

It is preferred that the infrared fluorophores absorb strongly atwavelengths below about 850 nm, since petroleum hydrocarbons haveinherent interfering absorption of wavelengths above about 850 nm.

Growing concern about pollution from the use of petroleum fuels requiresthat any marker for petroleum hydrocarbons be added at the lowest levelspossible to minimize any discharges into the atmosphere duringcombustion. Thus, the infrared fluorophore is preferably added at thelowest levels needed to produce a consistently detectable signal,preferably at about 1 ppm or less, by near infrared detection means,when irradiated by a light source.

The term "light sources" refers to devices used to irradiate the sampleswith near infrared radiation having wavelength outputs from 670 to 850nm such as laser diodes, solid state lasers, dye lasers, incandescent,or any other known light source. Such light sources can be used inconjunction with wavelength selectors such as filters, monochromators,etc. The preferred light sources are those that have a maximum signal atthe maximum of the absorbance of the tagging fluorophore. Examplesinclude the laser diodes, light emitting diodes, or solid state lasers.

In the above method, it will be appreciated that near infrared detectionmeans denotes any apparatus capable of detecting fluorescence in therange described herein. Such detection means are the devices fordetecting photons emitted by the fluorescent samples at wavelengths ofabout 670 to 2500 nm such as photomultiplier tubes, solid statedetectors, semi-conductor based detectors, or any such device. Thepreferred means of detection has an optimum sensitivity at the preferredwavelength region. Examples include the silicon photodiodes or germaniumdetectors.

In the above method, the phrase "detectibly different wavelength orwavelengths" refers to phenomenon that fluorescence by one or more ofthe near infrared fluorophores will occur at a different wavelength (orwavelengths in the case of two or more fluorophores) and such differencewill, by necessity be one that is capable of detection. Using state ofthe art detection equipment it is believed that such differences inabsorption/fluorescence of as little as 20 nm in wavelength can bediscerned. Of course, this limitation is not critical and will decreaseas detection methodology improves.

Thus, the presence of a near infrared fluorophore (NIRF) provides highlyeffective tags for identification of petroleum products. Ideally, asnoted above, the NIRF "tag" should have good thermal stability andlittle light absorption in the visible region; that is they shouldimpart little or no color to the petroleum product to which the NIRF iscopolymerized or admixed with. Also, they should have strong absorptionof near infrared light (high molar extinction coefficients,e.g., >20,000) and have strong fluorescence in the near infrared overthe wavelengths of about 670-2500 nm. To produce essentially "invisible"tags the near infrared fluorescent compounds must absorb little if anylight having wavelengths in the 400-670 nm range; however, since thecompounds are present in extremely low concentrations, a small amount ofabsorption may be tolerated without imparting significant color.

The preferred near infrared fluorescent compounds which are useful inthe practice of the invention are selected from the classes ofphthalocyanines, 2,3-naphthalocyaninessquaraines (squaric acidderivatives) and croconic acid derivatives and correspond to Formulae I,II, III, and IV, respectively: ##STR1## wherein Pc and Nc represent thephthalocyanine and naphthalocyanine moieties of Formulae Ia and IIa,##STR2## respectively, covalently bonded to hydrogen or to varioushalometals, organometallic groups, and oxymetals including AlCl, AlBr,AlF, AlOR₅, AlSR₅, SiCl₂, SiF₂, Si(OR₆)₂, Si(SR₆)₂, Zn or Mg, wherein R₅and R₆ are selected from hydrogen, alkyl, aryl, heteroaryl, alkanoyl,arylcarbonyl, arylaminocarbonyl, trifluoroacetyl, ##STR3## groups of theformula ##STR4## wherein R₇, R₈ and R₉ are independently selected fromalkyl, phenyl or phenyl substituted with alkyl, alkoxy or halogen;

X is selected from oxygen, sulfur, selenium, tellurium or a group of theformula N-R₁₀, wherein R₁₀ is hydrogen, cycloalkyl, alkyl, acyl,alkylsulfonyl, or aryl or R₁₀ and R taken together form an aliphatic oraromatic ring with the nitrogen atom to which they are attached;

Y is selected from alkyl, aryl, heteroaryl, halogen or hydrogen;

R is selected from hydrogen, unsubstituted or substituted alkyl,alkenyl, alkynyl,

C₃ -C₈ cycloalkyl, aryl, heteroaryl, alkylene ##STR5##

--(X-R)_(m) is one or more groups selected from alkylsulfonylamino,arylsulfonylamino, or a group selected from the formulae --X(C₂ H₄O)_(z) R, ##STR6##

wherein R is as defined above; Z is an integer of from 1-4; or two--(X-R)_(m) groups can be taken together to form divalent substituentsof the formula ##STR7##

wherein each X₁ is independently selected from --O--, --S--, or --N-R₁₀and A is selected from ethylene; propylene; trimethylene; and suchgroups substituted with lower alkyl, lower alkoxy, aryl and cycloalkyl;1,2-phenylene and 1,2-phenylene containing 1-3 substituents selectedfrom lower alkyl, lower alkoxy or halogen; R' and R" are independentlyselected from lower alkyl and cycloalkyl; R₁ and R₂ are independentlyselected from hydrogen, alkyl, alkoxy, halogen, aryloxy, alkylthio,arylthio, alkylsulfonyl, arylsulfonyl, alkylsulfonylamino,arylsulfonylamino, cycloalkylsulfonylamino, unsubstituted andsubstituted carbamoyl and sulfamoyl, alkoxycarbonyl,cycloalkoxycarbonyl, alkanoyloxy, ##STR8##

R₃ and R₄ are independently selected from hydrogen, lower alkyl, alkenylor aryl; n is an integer from 0-16; n₁ is an integer from 0-24, m is aninteger from 0-16; m₁ is an integer from 0-24; provided that the sums ofn+m and n₁ +m₁ are 16 and 24, respectively.

In the definitions of the substituents (Y)n, (Y)n₁, --(XR)m and(--X--R)m₁ these substituents are not present when n, n₁, m and m₁ arezero, respectively. Substituents (X--R)m and (Y)n are present incompounds Ia on the peripheral carbon atoms, i.e. in positions 1, 2, 3,4, 8, 9, 10, 11, 15, 16, 17, 18, 22, 23, 24, 25 and substituents (X-R)m₁and (Y)n₁ are present on the peripheral carbon atoms of IIa, i.e. inpositions 1, 2, 3, 4, 5, 9, 10, 11, 12, 13, 14, 18, 19, 20, 21, 22, 23,27, 28, 29, 30, 31, 32 and 36.

In a preferred embodiment of this invention the near infraredfluorescing compound is a squaraine compound of Formula III, wherein R₁and R₂ are independently alkoxycarbonyl.

In a further preferred embodiment of this invention, the near infraredfluorescing compound is a 2,3-naphthalocyanine compound of Formula II,wherein the naphthalocyanine moiety is bonded (at the 37 and 39positions) to hydrogen, AlCl, AlOH, AlOR₅, SICl₂, Si(OH)₂, Si(OR₆)₂, Znor Mg, m₁ is 0, Y is selected from hydrogen and alkyl and n₁ is 24 withY groups representing at least four alkyl or aryl groups.

In a further preferred embodiment of this invention, the near infraredfluorescing compound is a phthalocyanine compound of Formula I, whereinX is oxygen, R is aryl or alkyl, Y is hydrogen, m is 4, and n is 12; andwherein the phthalocyanine moiety is bonded (at the 29 and 31 positions)to hydrogen, AlCl, AlOH, AlOCOCF₃, AlOR₅, SICl₂, Si(OH)₂, or Si(OR₆)₂,Zn or Mg.

In a further preferred embodiment, the phthalocyanine andnaphthalocyanine compounds are bonded to hydrogen, i.e., at the 29 and31 positions of the phthalocyanine and the 37 and 39 position of thenaphthalocyanine.

In an especially preferred embodiment, the phthalocyanine,naphthalocyanine squaraine and croconic acid derivatives consist ofcarbon, hydrogen, and nitrogen atoms.

Other examples of preferred near infrared fluorescing compounds andmoieties can be found in the tables below.

The term "lower alkyl" is used to represent straight or branched chainhydrocarbon radicals containing 1-6 carbons.

In the terms alkyl, alkoxy, alkylthio, alkylsulfonyl, alkoxycarbonyl,alkanoyl and alkanoyloxy, the alkyl portion of the groups contain 1-20carbons and may contain straight or branched chains.

The term "cycloalkyl" is used to represent a cyclic aliphatichydrocarbon radical containing 3-8 carbons, preferably 5 to 8 carbonsand these radicals substituted by one or more groups selected from thegroup of alkyl, alkoxy or alkanoyloxy.

The alkyl and lower alkyl portions of the previously defined groups maycontain as further substituents one or more groups selected fromhalogen, cyano, C₁ -C₆ -alkoxy, cycloalkyl, aryl, C₁ -C₆ -alkylthiol,arylthio, aryloxy, C₁ -C₆ -alkoxycarbonyl or C₁ -C₆ -alkanoyloxy.

The term "aryl" includes carbocyclic aromatic radicals containing 6-18carbons, preferably phenyl and naphthyl, and such radicals substitutedwith one or more substituents selected from alkyl, alkoxy, halogen,--CH═N--alkyl, alkylthio, N(alkyl)₂, trifluromethyl, cycloalkyl,--CH═N--C₆ H₄ --CO₂ alkyl, alkoxycarbonyl, alkanoylamino,alkylsulfonylamino, arylsulfonylamino, cycloalkylsulfonylamino,alkanoyloxy, cyano, phenyl, phenylthio and phenoxy.

The term "heteroaryl" is used to represent mono or bicyclic heteroaromatic radicals containing at least one "hetero" atom selected fromoxygen, sulfur and nitrogen or a combination of these atoms. Examples ofsuitable heteroaryl groups include: thiazolyl, benzothiazolyl,pyrazolyl, pyrrolyl, thienyl, furyl, thiadiazolyl, oxadiazolyl,benzoxazolyl, benzimidazolyl, pyridyl, pyrimidinyl and triazolyl. Theseheteroaryl radicals may contain the same substituents listed above aspossible substituents for the aryl radicals. The term triazolyl alsoincludes structure V and mixed isomers thereof, ##STR9##

wherein R₁₁ is hydrogen or selected from alkyl and alkyl substitutedwith one or two groups selected from halogen, alkoxy, aryl, cyano,cycloalkyl, alkanoyloxy or alkoxycarbonyl.

The terms "alkenyl and alkynyl" are used to denote aliphatic hydrocarbonmoiety having 3-8 carbons and containing at least one carbon-carbondouble bond and one carbon-carbon triple bond, respectively.

The term halogen is used to include bromine, chlorine, fluorine andiodine.

The term "substituted alkyl" is used to denote a straight or branchedchain hydrocarbon radical containing 1-20 carbon atoms and containing assubstituents 1 or 2 groups selected from halogen, cycloalkyl, cyano, C₁-C₆ alkoxy, aryl, C₁ -C₆ alkylthio, arylthio, aryloxy, C₁ -C₆alkoxycarbonyl, or C₁ -C₆ alkanoyloxy.

The term "substituted carbamoyl" is used to denote a radical having theformula --CONR₁₂ R₁₃, wherein R₁₂ and R₁₃ are selected fromunsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl,heteroaryl, or R₁₂ and R₁₃ when alkyl may be combined to form a 5-8membered ring which may be substituted with 1-4 lower alkyl groups.

The term "substituted sulfamyl" is used to denote a radical having theformula --SO₂ NR₁₂ R₁₃, wherein R₁₂ and R₁₃ are as defined above.

The term "alkylene" refers to a divalent C₁ -C₂₀ aliphatic hydrocarbonmoiety, either straight or branched-chain, and either unsubstituted orsubstituted with one or more groups selected from alkoxy, halogen, aryl,or aryloxy.

The term "acyl" refers to a group of the formula R° C(O)--O--, whereinR° is preferably a C₁ -C₂₀ alkyl moiety. The term "alkyl sulfonyl"refers to a group of the formula R° SO₂ --, wherein R° is as defined foracyl.

Typical alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl,n-hexyl, isohexyl, heptyl, octyl, nonyl, 2-ethylhexyl, decyl, undecyl,dodecyl, tetradecyl, hexadecyl, octadecyl and eicosyl.

Typical cycloalkyl groups include cyclopentyl, cyclohexyl, cycloheptyl,2,3 and 4-methylcyclohexyl, 3,4-dimethylcyclohexyl,3,5-dimethylcyclohexyl and menthyl(2-isopropyl-5-methylcyclohexyl).

Typical aryl groups include phenyl, naphthyl, 2,3 and 4-methylphenyl,2,3 and 4-ethylphenyl, 4-isopropylphenyl, 2-n-propylphenyl,4-n-butylphenyl, 4-sec-butylphenyl, 4-tert-butylphenyl,2,6-diethylphenyl, 2-ethyl-6-methylphenyl, 2,4,6-trimethylphenyl,4-n-pentylphenyl, 4-octylphenyl, 4-cyclohexylphenyl, 4-dodecylphenyl,4-hexyloxyphenyl, 4-n-butoxyphenyl, 4-n-butoxycarbonylphenyl,4-hexyloxycarbonylphenyl, 4-isobutyloxyphenyl, 4-hexanoyloxyphenyl and4-(2-ethyl-hexyloxy)phenyl.

Typical --X-R groups include those listed in Table 1 below.

Two general routes are available for the synthesis of the NIRF compoundsof Formula I. Route I involves the reaction of substitutedphthalonitriles VI containing one or more leaving groups Z with one ormore nucleophiles VII (A. W. Snow and J. R. Griffith, Macro-molecules,1984, 17 (1614-1624), in the presence of a high boiling polar solventsuch as N,N-dimethyl-formamide, N,N-dimethylacetamide,N-methyl-2-pyrrolidinone, tetramethylurea, andhexamethylphospho-triamide to give intermediates VIII, which are furtherreacted by known procedures to give compounds I directly in a one-potprocess or to give the isoindoline derivatives IX, which are convertedinto the desired phthalocyanines I by known processes. ##STR10## Ofcourse, the starting compounds VI may contain further substituents whichare not replaced by reaction with the nucleophile. Route 2 employssimilar reaction conditions, as involved in initial step of Route 1, andmakes use of the reactivity of the halogen atoms in polyhalophthalocyanines X, containing 4-16 halogen atoms attached at peripheralcarbon atoms, with nucleophiles VII (see U.K. Patent No. 1,537,375 andU.S. Pat. No. 4,606,859) to give NIRF compounds I. ##STR11##

In the above nucleophilic reactions utilized in Routes 1 and 2, thebase, or acid binding agent, may be an alkali metal hydroxide, an alkalimetal bicarbonate or an alkali metal carbonate. For example, sodiumcarbonate, potassium carbonate, lithium hydroxide, sodium hydroxide,sodium bicarbonate and suitable bases.

The 2,3-naphthalocyanines of Formula II can be prepared by reacting2,3-naphthalene-dicarbonitrile compounds XI to give1,3-diiminobenz[f]-isoindolines XII, which are then converted to thenaphthalocyanines of Formulae II by known procedures [J.A.C.S. 1984,106, 7404-7410; U.S. Pat. No. 5,039,600, incorporated herein byreference; Zn. Obshch. Khim, 1972, 42(3), 696-9 (CA 77: 141469m); andJap. Pat. 61,215,663 (CA 106:86223s)]. ##STR12## Intermediate compoundsXI which contain one or more electron donating groups (--X-R) areconveniently prepared by reacting intermediate2,3-naphthalenecarbonitriles XIII ##STR13## containing replaceablehalogens with one or more nucleophiles under reaction conditions whichfavor nucleophilic displacements (J. Heterocyclic Chem. 1990, Vol. 27,Iss. 7, pp 2219-20).

The squaraines of Formula III can be prepared by reacting thecorresponding unsubstituted and substituted1,3-dihydro-2-methylene-1,1-dimethyl-1H-benz[e]indoles with squaric acidIS. Cohen, et al., JACS, 81, 3480 (1959)]. The reactions of squaric acidare well known in the art [R. West, editor, OXOCARBONS, Academic Press,New York, 1980, pp 185-231; G. Maahs and P. Hagenberg, Angew. Chem.internat. Edit., Vol. 5 (1966), No. 10, p 888; A. H. Schmidt, Synthesis,December 1980, p, 961]. The intermediate1,3-dihydro-2-methylene-1,1-dimethyl-H-benz[e]indoles XIV can besynthesized by known procedures [U.S. Pat. No. 5,030,708, incorporatedherein by reference]. The synthetic route is illustrated as follows:##STR14##

Intermediate 1,3-dihydro-2-methylene-1,1-dimethyl-H-benz[e] indoles XIVare reacted with squaric acid XV as shown to produce the squaraines. Ofcourse, an unsymmetrical derivative is obtained as one of the componentsof the mixture prepared by reacting a mixture of two or more differentintermediate benz[e]indole compounds XIV with squaric acid.

Croconic acid derivatives IV are prepared by the same procedure as thesquaraines, except that croconic acid is used instead of squaric acid.

The preferred compounds which are useful in the practice of theinvention contain one or a multiplicity of hydrocarbon moieties whichcan impart adequate solubility in the petroleum hydrocarbons. Usuallythe hydrocarbon moieties contain at least one straight or branched chainC₄ -C₂₀ groups, which may be in combination with one or more aryl orcycloalkyl groups. In general, if only one or two hydrocarbon moietiesare present the alkyl portion of the moiety should contain at leasteight carbon atoms.

A convenient method for introducing adequate hydrocarbon moieties intothe infrared fluorophore structure is to react infrared fluorophores(FL) containing electron deficient functional groups such as carboxy,carbonyl chloride, carbalkoxy or sulfonyl chloride with hydrocarbon richcompounds which contain electron rich groups such as alcohols and aminesto give the corresponding esters and amides. Or, on the contrary, onecan react infrared fluorophores (FL) containing functional amines andhydroxy groups with hydrocarbon rich compounds which contain functionalgroups such as carboxy, carbonyl chloride, carbalkoxy or sulfonylchloride. Preferably, the carbalkoxy groups should be lower carbalkoxy,e.g. carbomethoxy, to promote easier transesterification.

Typical reactions include the following: ##STR15##

wherein n is 1-8 and Z is a hydrocarbon rich moiety. Reaction 1 may beconveniently carried out by heating the infrared fluorophore whichcontains the carbomethoxy group(s) with excess hydrocarbon richalcohol(s), ZH, in the presence of a transesterification catalyst suchas titanium IV isopropoxides while allowing the methanol thus formed tobe removed. Reactions 2, 3 and 4 are normally performed in the presenceof base to facilitate completion of the reaction. Such bases includealkali metal carbonates, alkali metal bicarbonates, amines, e.g.trialkylamines and pyridine. To promote the formation of fluorophoreshaving optimum solubility it is desirable that they be largely amorphousand to have low melting points or even be liquids. One method toaccomplish this desired feature is to intentionally produce mixtures offluorophores, preferably containing a high degree of branching in thealkyl portion of the hydrocarbon moiety.

The following examples illustrate further the synthetic methods whichare used in preparing the compounds which are useful in the practice ofthe invention.

Experimental Section EXAMPLE 1

A mixture of methyl 1,1,2-trimethyl-1H-benz[e]-indole-7-carboxylate(tautomer is methyl 1,3-dihydro-2-methylene-1,1-dimethyl-1H-benz[e]indole-7-carboxylate), 2.67 g (0.01 m) (see U.S. Pat. No. 5,030,708),squaric acid (0.57 g, 0.005 m) and 2-ethoxyethanol (40 g) was heated atreflux under nitrogen for 16 hours. The reaction mixture was cooled withan ice bath and the green solid collected by filtration, washed withisopropanol and dried in air. Recrystallization from 2-ethoxyethanol (20mL), collection of the solid by filtration, washing of the solid withisopropanol and drying gave the pure product. Mass spectrometryindicated mostly the following structure plus a small amount ##STR16##of the mono 2-ethoxyethyl ester which had been produced bytransesterification. In methylene chloride an absorption maximum (A max)was observed in the visible-near infrared absorption spectrum at 690 nm(ε--214, 287).

EXAMPLE 2

A mixture of methyl 1,1,2-trimethyl-1H-benz[e]-indole-7-carboxylate(tautomer is methyl1,3-dihydro-2-methylene-1,1-dimethyl-1H-benz[e]-indole-7-carboxylate)[2.67 g (0.01 m)], croconic acid trihydrate, (0.98 g, 0.005 m) and2-ethoxyethanol (40 g) was heated at reflux under nitrogen for 16 hours.After allowing to cool, the reaction mixture was filtered and the solidwas washed with methanol and dried in air (yield 2.2 g). The product wasreslurried in boiling methanol, collected by filtration, washed withmethanol and dried in air (yield--2.13 g). Mass spectrometry indicatedmostly the following structure: ##STR17##

In methylene chloride an absorption maximum (λ max) was observed in thevisible--near infrared absorption spectrum at 816 nm.

EXAMPLE 3

A mixture of methyl 1,1,2-trimethyl-1H-benz[e]-indole-7-carboxylate(tautomer is methyl1,3-dihydro-2-methylene-1,1-dimethyl-1H-benz[e]-indole-7-carboxylate)[2.67 g (0.01 m)], squaric acid (0.57 g, 0.005 m), 2-ethylhexanol (30 g)and 2 drops of titanium IV isopropoxide was heated at reflux undernitrogen for 6 hours. The excess alcohol was removed by heating on asteam bath under vacuum. A solid was produced by treating the residuewith hexane (some solubility) and was collected by filtration, washedwith petroleum ether and dried in air (yield 2.92 g).

Mass spectrometry and proton NMR supported the following structure:##STR18##

In toluene, an absorption maximum at 698 nm was observed in the nearinfrared absorption spectrum (E-192,197).

EXAMPLE 4

A 300 mL 3-neck round-bottom flask was equipped with a magnetic stirrer,thermometer and gas inlet tube. Methanol (50 mL) was added followed bysodium metal (0.66 g, 0,029 mole) with stirring to facilitate reactionand solution, with a slow nitrogen purge applied. To this solution wasadded 12.54 g (0.058 mole) of 4-phenoxyphthalonitrile (A. W. Snow and J.R. Griffith, Macromolecules, 1984, 17, 1614-24), followed by additionalmethanol (50 mL). Anhydrous ammonia was bubbled in under the surface,giving an exotherm to 45° C. and total solution. The ammonia additionwas continued until no more starting material was evident by thin-layerchromatography. The solution was clarified by filtering through a pad ofDicalite filter aid which had a small layer of charcoal on it and thefiltrate drowned into water. The oily product layer thus produced waswashed by decantation with 500 mL portions of water (4-5 times or untilpH reached about 7-8). After the final wash water was decanted off,methanol was added to dissolve the product, which crystallized uponstirring overnight at room temperature. After being collected byfiltration, the greenish-yellow solid was washed with methylene chlorideand dried in air. The yield was 13.75 g, 91.1% of the theoretical yield.Mass spectrometry showed the product to consist largely of the desired5-phenoxy-1,3-diiminoisoindoline.

EXAMPLE 5

A mixture of 5-phenoxy-1,3-diiminoisoindoline (3.68 g, 0.016 m) (fromExample 4), 1,2,3,4-tetrahydro-aphthalene (20 mL) and tri-n-butylamine(10 mL) was stirred under a nitrogen sweep. Aluminum chloride (3.19 g,0.024 m) was added to give a slurry. After the reaction mixture washeated at about 180° C. for 4 hours, it was allowed to cool to roomtemperature and diluted with methanol to enhance solubility tofacilitate transfer into about 500 mL of ice-water mixture containing 10mL HCl. The somewhat "greasy" solid product was collected by filtrationand washed with dilute HCl. The filter cake was washed on the filterwith cyclohexane and finally washed thoroughly with ethyl acetate anddried in air. Mass Spectrometry indicated good quality 2(3), 9(10),16(17), 23(24)-tetraphenoxy-Pc-Al-Cl (Pc=phthalocyanine moiety) havingthe desired molecular weight of 942 (1.56 g, 41.4% of the theoreticalyield).

EXAMPLE 6

A portion (110 mg) of the tetraphenoxy-chloroluminumphthalo-cyanine ofExample 5 was dissolved in trifluoroacetic acid (10 mL) and allowed toevaporate at room temperature. As evidenced by mass spectrometry, theresidual product was mostly 2(3), 9(10), 16(17),23(24)-tetraphenoxy-Pc-AlOCOCF₃, molecular weight 1020. In methylenechloride, absorption maxima were observed at 696 nm (ε--126,170), 629 nm(ε--26,697), 341 nm (ε--58,872) and 292 nm (ε--30,600) in theultraviolet, visible, near-infrared absorption spectra.

EXAMPLE 7

A reaction mixture of tetraphenoxy-chloroaluminum phthalocyanine (0.94g) of Example 5, dimethyl-3-ydroxyisophthalate (0.24 g) and pyridine (20g) was heated at reflux for 24 hours and allowed to cool to roomtemperature. Isopropanol (20 mL) was added and then by the addition ofwater, the phthalocyanine (Pc) product was precipitated, [2(3), 9(10),16(17), 23(24)-tetraphenoxy-pc-AlOC₆ H₃ -3,5-di--CO₂ CH₃ ], which wascollected by filtration, washed with water and dried in air (yield--0.90g). In methylene chloride, absorption maxima were observed at 696 nm(104,585), 626 nm (32,882) and 343 nm (64,090) in the ultraviolet,visible and near infrared absorption spectra.

EXAMPLE 8

A mixture of 5-phenoxy-1,3-diiminoisoindoline (3.68 g, 0.016 mole),silicon tetrachloride (4.0 g, 0.024 mole) 1,2,3,4-tetrahydronaphthalene(20 mL) and tri-n-butylamine (10 mL) was heated under nitrogen at about200° C. for 40 minutes, allowed to stir overnight at room temperatureand reheated to 180° C. and held for about 2.0 hours. After cooling toroom temperature, the reaction mixture was diluted with 30 mL ofmethanol, filtered, and the collected solid washed with methanol anddried in air (yield--2.71 g, 69.3% of the theoretical yield). Massspectrometry supported the structure: 2(3), 9(10), 16(17),23(24)-tetra-phenoxy-Pc--Si-(Cl)₂.

EXAMPLE 9

A mixture of the tetraphenoxy-dichlorosiliconphthalocyanine (0.49 g) ofExample 8, methyl 4-hydroxy-benzoate (0.16 g) and pyridine (5 g) washeated at reflux for 3 hours under nitrogen. To the cooled reactionmixture were added isopropanol (20 mL) and then water (20 mL) withstirring. The product was collected by filtration, washed with water anddried in air. Mass spectrometry supports the structure: 2(3), 9(10),16(17), 23(24)-tetraphenoxy-pc-Si-(OC₆ H₄ --4--CO₂ CH₃)₂.

EXAMPLE 10

A mixture of silicon phthalocyanine dichloride (0.2 g) was dissolved intrifluoroacetic acid (10 mL) and the reaction mixture allowed to standin a hood in an evaporating dish until all the excess trifluoroaceticacid had evaporated. Absorption maxima were observed at 691 nm(ε--168,645), 659 nm (ε--21,596), 622 nm (ε--4,789), 356 nm (ε--50,090)and 334 nm (ε--44,608) in the ultraviolet-visible-near infraredabsorption spectra. The product was assumed to be silicon phthalocyaninetrifluroacetate [Pc-Si (OCOCF₃)₂ ].

EXAMPLE 11

A reaction mixture of Nc-Si(OH)₂ (1.5 g) (J.A.C.S. 1984, 106,7404-7410), pyridine (150 mL) and chloro dimethylphenylsilane (10 mL)was heated at reflux for 5 hours and then allowed to cool. Someinsolubles were filtered off and the filtrate stripped on a rotaryevaporator under vacuum. Pentane (300 mL) was added to the residue toproduce a solid upon stirring which was collected by filtration, washedwith 50/50 acetone/water, then with pentane and dried in air. The solid(1.9 g) was reslurried in hot pentane (300 mL) and filtered hot. Thesolid thus obtained was washed with pentane and air dried (yield--1.5g). Mass spectrometry supported the following structure Nc-Si[O-si(CH₃)₂ C₆ H₅ ]₂.

EXAMPLE 12

A mixture of 5-phenoxy-1,3-diminoiosindoline (11.04 g, 0,047 m),tetrahydronaphthalene (60 mL), and tri-n-butyl amine (30.0 mL) wasstirred. Silicon tetra-chloride (12.0 g, 0.071 m) was then added and thereaction mixture was heated slowly to reflux and held for 4 hours. Afterallowing to cool, the reaction mixture was diluted with an equal volumeof methanol. The product, 2(3), 9(10), 16(17), 23(24)tetraphenoxy-PcSiCl₂ was collected by filtration, washed with methanol,then washed with water and dried in air. The yield of product was 7.7 g.

EXAMPLE 13

A portion (7.0 g, 0.0072 m) of the product of Example 11, methyl4-hydroxybenzoate (2.4 g, 0.016 m) and pyridine (150 mL) were mixed andheated at reflux with stirring for 20 hours. The reaction mixture wascooled and then drowned into 500 mL water. Added about 50 mL ofsaturated sodium chloride solution with stirring. The product wascollected by filtration, washed with water and dried in air (yield--7.1g). Mass spectrometry confirmed the product to be the desired product[2(3), 9(10), 16(17), 23(24) tetraphenoxy-PcSi-(OC₆ H₄ -4--CO₂ CH₂)₂ ].Absorption maxima were obtained at 649 nm and 691 nm in the lightabsorption spectrum in methylene chloride.

EXAMPLE 14

A mixture of 3-phenylnaphthalene-2,3-dicarboxylic acid anhydride (6.26g, 0.023), urea (45.0 g), ammonium molybdate (0.10 g) and aluminumchloride (0.90 g, 0.006 m) was heated under nitrogen at about 250° C.with stirring for 2.0 hours. Heat was removed and the darkbrownish-black solid transferred into boiling water with stirring. Theproduct was collected by filtration, reslurried in dilute hydrochloricacid, filtered, reslurried in dilute ammonium hydroxide, filtered,reslurried in hot water and finally filtered, washed with water anddried in air (yield--5.0 g). The product was presumed to be 5(36),9(14), 18(23), 27(32) tetraphenyl-NcAlCl (Nc=naphthalocyanine moiety).

EXAMPLE 15

A mixture of 3,6-di-n-butoxy phthalonitrile (2.50 g, 0.0092 m), urea(20.0 g), ammonium molybdate (0.1 g) and aluminum chloride (0.41 g,0.003 m) was heated under nitrogen with stirring at 250° C. in a Belmontmetal bath for 2.0 hours. The dark solid was removed, pulverized andthen added to a dilute HCl solution and stirred. The product was thencollected by filtration, reslurried in dilute ammonium hydroxide,filtered, washed with water and dried in air. The product was presumedto be 1,4,8,11,15,18,22,25-octa-n-butoxy-PcAlCl.

EXAMPLE 16

A mixture of 6-t-butyl-2,3-dicyanonaphthalene (23.4, 0.10 m), aluminumchloride (3.5 g) and urea (23.0 g) was heated at 218°-220° C. for 1.0hour in a Belmont metal bath with stirring. The reaction mixture wasallowed to cool and the solid was pulverized using a mortar and pestleand then slurried in 10% NaOH, collected by filtration, washed withmethanol and dried in air (yield 10.3 g). Based on mass spectrometry, itwas concluded that the product was a mixture of 2(3), 11(12), 20(21),29(30)-tetra-t-butyl-NcAlCl and 2(3), 11(12), 20(21),29(30)-tetra-t-butyl-NcAlOH.

EXAMPLE 17

A mixture of 3-[2-(carbo-n-pentoxy)phenylthio]-phthalonitrile (7.0 g,0.02 m), urea (28.6 g, 0.47 m) and aluminum chloride (0.713 g, 0.0053 m)was stirred in a Belmont metal bath (230° C.). The reddish melt wasstirred slowly until homogeneous, then rapidly at about 215°-225° C. for10 minutes. Stirring and heating were continued under a stream of N₂ forabout 1.25 hours. The reaction flask was removed from the metal bath andallowed to cool. The solid was removed from the flask, placed in conc.HCl, ground to a good slurry in a mortar and pestle, filtered and washedwith boiling water. Finally, the dark green solid was placed in freshconc. HCl, the mixture boiled and then the solid was collected byfiltration, washed with hot water and dried in air. The product, 1(4),8(11), 15(18), 22(25)-tetra[2-carbo-n-pentoxy)phenylthio]-PcAlCl, whendissolved in N,N-dimethylformamide had a maximum absorption at 714 nm inthe light absorption spectrum.

EXAMPLE 18

A mixture of aluminum phthalocyanine chloride (5.0 g, 0.0087 m),dimethyl 5-hydroxyisophthalate (1.83 g, 0.0087 m) and pyridine (25 mL)was heated and stirred at reflux for about 18 hours under nitrogen andthen after cooling was drowned into water (500 mL). The green solid wascollected by filtration, washed with water (1 l) and air dried. Theproduct, PcAlOC₆ H₃ -3,5-diCO₂ CH₃, had an absorption maximum at 675 nm(ε--198,481) in the light absorption spectrum in N,N-dimethylformamide.

EXAMPLE 19

A mixture of 4-phenylthiophthalonitrile (2.36 g, 0.01 m), aluminumchloride (0.35 g, 0.0026 m), ammonium molybdate (0.10 g) and urea (40.0g) was placed in a flask and heated in a Belmont metal bath at about200° C. with stirring for 2.5 hours at about 245° C. The flask wasremoved from the metal bath and allowed to cool. The solid was ground ina mortar and pestle, added to hot water, collected by filtration, washedwith hot water, 5% HCl, dilute NH₄ OH, hot water, 10% HCl, warm waterand air dried (yield 2.50 g, 99.4% of the theoretical yield). Anabsorption maximum was observed at 701 nm in the light absorptionspectrum of the product, 2(3), 9(10), 16(17),23(24)-tetraphenylthio-PcAlCl, when dissolved in N,N-dimethylformamide.

EXAMPLE 20

A mixture of a portion (2.33 g, 0.0023 m) of the product of Example 19,dimethyl 5-hydroxyisophthalate (0.49 g, 0.0023 m) and pyridine (25 g)was heated and stirred at reflux under N₂ for 16 hours and then allowedto cool. The product [2(3), 9(10), 16(17), 23(24)-tetraphenylthio-AlOC₆H₃ -3,5-diCO₂ CH₃ ] was isolated by drowning into water (500 mL) andcollecting by filtration and was then washed with water, acetone andmethanol and dried in air. Attempts to obtain light absorption spectrumfailed because of insolubility of the product.

EXAMPLE 21

A mixture of aluminum naphthalocyanine chloride (0.98 g, 0.00126 m)(Aldrich Chemical Co.), dimethyl 5-hydroxyisophthalate (0.21 g, 0.001m), potassium carbonate (0.09 g) and dimethyl sulfoxide (23 g) washeated and stirred under N₂, at 95°-100° C. for about 8 hours. Verylittle solution of reactants seemed to have occurred. Added pyridine (23mL) and heated at reflux under N₂ for about 96 hours (over the weekend).The green reaction mixture was allowed to cool and then drowned inwater. The product (NcAl-OC₆ H₃ -3,5-di-CO₂ CH₃) was collected byfiltration, washed with water, reslurried in water, collected again byfiltration, washed with water and dried in air (yield--0.94 g, 79.0% ofthe theoretical yield. An absorption maximum at 779 nm was observed inthe light absorption spectrum in dimethyl sulfoxide.

EXAMPLE 22

A mixture of silicon naphthalocyanine dichloride (0.20 g, 2.46×10⁻⁴ m),methyl 4-hydroxybenzoate (0.075 g, 4.93×10⁻⁴ m), dimethyl sulfoxide(11.4 g) and pyridine (10.5 g) was heated and stirred under N₂ at refluxfor about 64 hours. The reaction mixture was drowned into ice watermixture and the product [NcSi(OC₆ H₄ -4---CO₂ CH₃)₂ ] was collected byfiltration, washed with water and dried in air. An attempt to obtain theabsorption maximum in dimethyl sulfoxide (very slightly soluble) gave anapparent maximum at 773 nm in the light absorption spectrum.

EXAMPLE 23

A portion (2.0 g) of the product of Example 16 was added to conc. HCl(200 mL) and the mixture refluxed for 24.0 hours. The product 2(3),11(12), 20(21), 29(30)-tetra-t-butylNcAlCl, was collected by filtration,washed with conc. HCl, washed with water and dried in air. An absorptionmaximum at 779 nm was observed in the light absorption spectrum inN,N-dimethylformamide.

EXAMPLE 24

A mixture of 3-phenoxyphthalonitrile (4.4 g, 0.02 m), aluminum chloride(0.8 g, 0.005 m) was placed in a Belmont metal bath at 250° C. andheated with stirring for 30 minutes under a nitrogen sweep. The reactionmixture was allowed to cool and the solid product was ground using amortar and pestle and then slurried in hot water (500 mL) with stirring.After being collected by filtration, the product [1(4), 8(11), 15(18),22(25)-tetraphenoxy-PcAlCl] was washed with boiling water (1 l), washedwith cyclohexane, washed with n-hexane and dried in air (yield--4.3 g,91.3% of the theoretical yield). An absorption maximum was observed at700 nm in the light absorption spectrum in N,N-dimethylformamide.

EXAMPLE 25

A portion (2.0 g, 0.002 m) of the product of Example 24, dimethyl5-hydroxyisophthalate (0.5 g, 0.002 m) and pyridine (100 mL) were mixedand heated with stirring at reflux for 24 hours. The reaction mixturewas drowned into water and the solid was collected by filtration, washedwith cyclohexane, washed with n-hexane and dried in air (yield 2.1 g,94.2% of the theoretical yield). The product [1(4), 8(11), 15(18),22(25)-tetraphenoxy-PcAlOC₆ H₃ -3,5-diCO₂ CH₃ ] had an absorptionmaximum at 699 nm in the light absorption spectrum inN,N-dimethylformamide.

EXAMPLE 26

A mixture of 3-phenylthiophthalonitrile (11.8 g, 0.05 m) aluminumchloride (1.8 g, 0.014 m) was heated in a Belmont metal bath under anitrogen sweep at about 250° C. for 1 hour. The reaction mixture wasallowed to cool and the solid was ground in a mortar and pestle and thenslurried by stirring in a warm 6% HCl aqueous solution. The product[1(4), 8(11), 15(18), 22(25)-tetraphenylthio-PcAlCl] was collected byfiltration washed with warm water, washed with 6% HCl solution, washedwith warm water and dried in air. Field desorption mass spectrometryshowed a molecular ion of 1006, which supports the expected structure.An absorption maximum at 724 nm (ε--114,724) was observed in the lightabsorption spectrum in N,N-dimethyl-formamide.

EXAMPLE 27

A portion (5.03 g 0.005 m) of the product of Example 26, dimethyl5-hydroxyisophthalate (1.05 g, 0.005 m) and pyridine (250 mL) were mixedand heated at reflux for 48 hours. The cooled reaction mixture was thendrowned into water and the solid product was washed with warm water anddried in air (yield--5.4 g). A portion (1.5 g) of the product wasdissolved in tetrahydrofuran (25.0 mL) and the solution placed on acolumn of activated aluminum oxide (150 mesh) (Aldrich Chem. Co.) andthen eluted with methylene chloride to remove a fast moving band. Theremaining product was eluted with methanol and then the methanol wasremoved by evaporation (yield--0.72 g). Field desorption massspectrometry supported the desired product, 1(4), 8(11), 15(18),22(25)-tetraphenylthio-pcAlOC₆ H₃ -3,5-diCO₂ CH₃. An absorption maximumwas observed at 729 nm (ε--128,526) in the light absorption spectrum ofthe chromatographed product in N,N-dimethylformamide.

EXAMPLE 28

A mixture of 6-t-butyl-1,3-diiminobenz(b) isoindoline (15.0 g, 0.06 m)silicon tetrachloride (10.8 mL), tetrahydronaphthalene (100.0 mL) andtributylamine (40.0 mL) was heated to reflux over a 1.0 hour period.After being refluxed for 3.0 hours, the reaction mixture was allowed tocool and then was treated with isopropanol (400 mL). The mixture wasthen drowned into water (1.0 l) and the solid [2(3), 11(12), 20(21),29(30)-tetra-t-butyl-NcSiCl₂ ] was collected by filtration, washed withwater and dried in air (yield--12.0 g). Absorption maxima were observedat 777 nm and 835 nm in the light absorption spectrum inN,N-dimethylformamide.

EXAMPLE 29

A mixture of 3-nitrophthalonitrile (8.65 g, 0.05 m), aluminum chloride(1.67 g, 0.0125 m) was heated in a Belmont metal bath under a nitrogensweep at about 250° C. for 1 hour. The reaction mixture was allowed tocool and the solid was ground in a mortar and pestle and then slurriedin a warm 6% HCl aqueous solution. The product [1(4), 8(11), 15(18),22(25)-tetranitro-PcAlCl] was collected by filtration, washed with warmwater, washed with 6% HCl solution, washed with warm water and dried inair.

EXAMPLE 30

A mixture of 2-3-dicyano-5-nitronaphthalene (8.9 g, 0.04 m), aluminumchloride (1.33 g, 0.01 m) was heated in a Belmont metal bath under anitrogecn sweep at about 250° C. for 1 hour. The reaction mixture wasallowed to cool and the solid was ground in a mortar and pestle and thenslurried in a warm 6% HCl aqueous solution. The product [1(4), 10(13),19(22), 29(31)-tetranitro-NcAlCl] was collected by filtration, washedwith warm water, washed with 6% HCl solution, washed with warm water anddried in air.

EXAMPLE 31

A stock solution of the infrared fluorophore of Example 3 in toluene wasprepared by dissolving 0.0089 g of fluorophore in 100 g of toluene(0.089 g/L, 890×10⁻⁴ g/L). Dilutions of 1/25, 1/100, 1/200 and 1/1000 togive concentrations of 356×10⁻⁵ g/L, 890×10⁻⁶ g/L, 445×10⁻⁶ g/L and890×10⁻⁷ g/L (8.9×10⁻⁵ g/L) were made. At the lower concentration levelscolor was invisible to the eye. When exposed to light generated by alaser diode at 670 nm all of the samples had detectable fluorescencewith a detector designed to detect infrared radiation having wavelengthsin the 700-720 nm range.

EXAMPLE 32

The stock solution of Example 31 was diluted at the ratio of 1/25,1/100, 1/200 and 1/1000 using premium grade gasoline to produceconcentrations of 356×10⁻⁵ g/L, 890×10⁻⁶ g/L, 445×10⁻⁶ g/L and 890×10⁻⁷g/L (8.9×10⁻⁵ g/L). No color was observable in the samples having thelower concentrations. When exposed to light generated by a laser diodeat 670 nm all of the samples had detectable fluorescence with a detectordesigned to detect infrared radiation having wavelengths in the 700-720nm range. Upon standing several days none of the infrared fluorophoreshad settled or crystallized out even in the higher concentrations.

                                      TABLE 1                                     __________________________________________________________________________    EXEMPLARY XR GROUPS                                                           XR                    XR                                                      __________________________________________________________________________    OCH.sub.2 CH(CH.sub.3).sub.2                                                                         ##STR19##                                              OCH.sub.4 H.sub.9 -n                                                                                 ##STR20##                                              OC(CH.sub.3).sub.3                                                                                   ##STR21##                                              OC.sub.12 H.sub.25 -n                                                                                ##STR22##                                              SCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 -n                                                      ##STR23##                                              S(CH.sub.2).sub.12 OCOCH.sub.3                                                                       ##STR24##                                              SC.sub.8 H.sub.17 -n                                                                                 ##STR25##                                              OCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 -n                                                      ##STR26##                                              OCH.sub.2 CHCH.sub.2                                                                                 ##STR27##                                              OCH.sub.2 CHCH.sub.2                                                                                 ##STR28##                                              SCH.sub.2 C.sub.6 H.sub.5                                                                            ##STR29##                                              SCH.sub.2 CH(OCOC.sub.4 H.sub.9 -n)CH.sub.2 OCOC.sub.4 H.sub.9 -n                                   OCH.sub.2 C.sub.6 H.sub.4 -4-COO(CH.sub.2).sub.6                              CH.sub.3                                                OCH.sub.2 C CH        OC.sub.6 H.sub.4 -4-CH.sub.2 COO(CH.sub.2).sub.7                              CH.sub.3                                                N(C.sub.4 H.sub.9 -n).sub.2                                                                         OCH.sub.2 CH.sub.2 CO.sub.2 C.sub.4 H.sub.9 -n          NHC.sub.6 H.sub.4 -4-C(CH.sub.3).sub.3                                                               OCH.sub.2 CH.sub.2 OCOCH.sub.2 CH(C.sub.2 H.sub.5)C                          .sub.4 H.sub.9 -n                                       N(C.sub.4 H.sub.9 -n)C.sub.6 H.sub.5                                                                OC.sub.6 H.sub.4 -4-OCH.sub.2 CH.sub.3                  N[C.sub.2 H.sub.4 OCO(CH.sub.2).sub.4 CH.sub.3 ].sub.2                                              OC.sub.6 H.sub.4 -4-OCH.sub.2 CH.sub.2 OCOC.sub.4                             H.sub.9 -n                                              NHC.sub.6 H.sub.11                                                                                   ##STR30##                                              N(C.sub.4 H.sub.9 -n)C.sub.6 H.sub.11                                          ##STR31##                                                                                           ##STR32##                                              OC.sub.6 H.sub.5      O(CH.sub.2 CH.sub.2 O).sub.2 COC.sub.3 H.sub.7 -n       OC.sub.6 H.sub.4 -4-COO(CH.sub.2).sub.12 CH.sub.3                                                    S(CH.sub.2 CH.sub.2 O).sub.2 COC.sub.4 H.sub.9 -n      SC.sub.6 H.sub.4 -4-COO(CH.sub.2).sub.17 CH.sub.3                                                   O(CH.sub.2 CH.sub.2 O).sub.4 COCH.sub.2 CH(C.sub.2                            H.sub.5)C.sub.4 H.sub.9 -n                              OC.sub.6 H.sub.3 -3,5-diCOO(CH.sub.2).sub.7 CH.sub.3                                                O(CH.sub.2 CH.sub.2 O).sub.3 CH.sub.3                   OC.sub.6 H.sub.3 -3,5-diCO.sub.2 (CH.sub.2).sub.5 CH.sub.3                                          O(CH.sub.2 CH.sub.2 O).sub.2 C.sub.6 H.sub.5            SC.sub.6 H.sub.4 -2-COOC.sub.4 H.sub.9 -n                                                           NH(CH.sub.2 CH.sub.2 O).sub.2 CO(CH.sub.2).sub.11                             CH.sub.3                                                SC.sub.6 H.sub.4 -3-CO.sub.2 CH.sub.2 CH(CH.sub.3).sub.2                      OC.sub.6 H.sub.4 -4-C.sub.2 H.sub.4 OCOC.sub.6 H.sub.11                       __________________________________________________________________________

    TABLE 2      SQUARAINE COMPOUNDS      ##STR33##      EX. NO. R.sub.1, R.sub.2 R.sub.3, R.sub.4 R', R"      33 7-CO.sub.2 (CH.sub.2).sub.3 CH.sub.3 CH.sub.3 CH.sub.3 34 7-CO.sub.2     C.sub.2 H.sub.5 C.sub.6 H.sub.5 CH.sub.3 35 7-CO.sub.2 (C.sub.6 H.sub.4     -4-CH(CH.sub.3).sub.2 C.sub.6 H.sub.4      -4-CH.sub.3 CH.sub.3 36 7-CONHCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4     H.sub.9 -n H CH.sub.3 37 7-CONHC.sub.2 H.sub.4 OCO(CH.sub.2).sub.6     CH.sub.3 H CH.sub.3 38 7-CON(CH.sub.3)C.sub.2 H.sub.4 OCOCH.sub.2     CH(CH.sub.3).sub.2 CH.sub.3 CH.sub.3 39 7-CON(CH.sub.3)C.sub.6 H.sub.11     H CH.sub.3 40 7-CONHC.sub.6 H.sub.11 C.sub.4 H.sub.9      -n CH.sub.3,CH.sub.2 CH.sub.3 41 7-CONHC.sub.6 H.sub.4 -4-C.sub.6     H.sub.11 H CH.sub.2 CH.sub.3,CH.sub.2 CH.sub.3 42 7-CONHCH.sub.2 C.sub.6     H.sub.10 -4-CH.sub.2 OH CH.sub.3 CH.sub.3,CH.sub.2 CH(CH.sub.3).sub.2 43     7-CONHC.sub.6 H.sub.4 -4-CO.sub.2 CH.sub.3 H CH.sub.3,CH.sub.2 CH.sub.2     CH(CH.sub.3).sub.2 44 7-SO.sub.2 N(CH.sub.3)(CH.sub.2).sub.6 CH.sub.3 H     CH.sub.3,CH(CH.sub.3).sub.2 45 7-SO.sub.2 N(C.sub.4 H.sub.9 -n).sub.2     CH.sub.3 CH.sub.2 CH(CH.sub.3).sub.2,CH.sub.2 CH.sub.3 46 7-SO.sub.2     N(CH.sub.3)C.sub.6 H.sub.11 CH.sub.3 (CH.sub.2).sub.5      CH.sub.3,(CH.sub.2).sub.5 CH.sub.3      47     ##STR34##      H CH.sub.3      48     ##STR35##      H CH.sub.3      49     ##STR36##      H CH.sub.3  50 7-SO.sub.2 NHCH.sub.2 C(CH.sub.3).sub.2 CH.sub.3 C.sub.6     H.sub.5 CH.sub.3 51 7-SO.sub.2 NH(CH.sub.2).sub.17 CH.sub.3 H CH.sub.3     52 7-SO.sub.2 NHC.sub.6 H.sub.4 -3-CO.sub.2 (CH.sub.2).sub.6 CH.sub.3 H     CH.sub.3 53 7-SO.sub.2 NHC.sub.6 H.sub.4 -4-(CH.sub.2).sub.11 CH.sub.3 H     CH.sub.3 54 7-SO.sub.2 NHC.sub.6 H.sub.4 -3-CH.sub.2      OCO(CH.sub.2).sub.10 CH.sub.3 CH.sub.3 CH.sub.3 55 7-SO.sub.2 NHC.sub.6     H.sub.10 -4-CH.sub.3 CH.sub.2 CHCH.sub.2 CH.sub.3 56 7-(CH.sub.2).sub.8     CH.sub.3 H CH.sub.3 57 7-OC.sub.6 H.sub.6 -4-OCH.sub.2      CH(CH.sub.3).sub.2 H CH.sub.3 58 7-(OC.sub.2 H.sub.4).sub.3 OCH.sub.3 H     CH.sub.3 59 7-S(CH.sub.2).sub.9 CH.sub.3 H CH.sub.3 60 7-SC.sub.6     H.sub.4 -4-C.sub.6 H.sub.11 H CH.sub.3 61 8-(CH.sub.2).sub.3 CH.sub.3     CH.sub.3 CH.sub.3 62 8-OCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 -n H     CH.sub.3 63 8-O(CH.sub.2).sub.11      CH.sub.3 H CH.sub.3 64 8-OCO(CH.sub.2).sub.6 CH.sub.3 H CH.sub.3 65     7-C.sub.6 H.sub.11 H CH.sub.3 66 7-COOC(CH.sub.3).sub.3 H CH.sub.3 67     7-CO.sub.2 (CH.sub.2).sub.3 CH(CH.sub.3).sub.2 H CH.sub.3 68 7-CO.sub.2     (CH.sub.2).sub.2 CH(CH.sub.3).sub.2 H CH.sub.3 69 7-CH.sub.2      CH(CH.sub.3)CH.sub.2 C(CH.sub.3).sub.2 CH.sub.3 H CH.sub.3      70     ##STR37##      C.sub.6 H.sub.5 CH.sub.3  71 7-SO.sub.2 C.sub.6 H.sub.4      -4-O(CH.sub.2).sub.3 CH(CH.sub.3).sub.2 H CH.sub.3 72 7-SO.sub.2     (CH.sub.2).sub.2 CH(CH.sub.3)CH.sub.2 CH.sub.3 H CH.sub.3 73 7-SO.sub.2     (CH.sub.2).sub.13 CH.sub.3 H CH.sub.3 74 7-SO.sub.2 C.sub.6 H.sub.4     -3-CO.sub.2 (CH.sub.2).sub.11 CH.sub.3 H CH.sub.3      75     ##STR38##      H CH.sub.3      76     ##STR39##      H CH.sub.3  77 7-NHSO.sub.2 (CH.sub.2).sub.11 CH.sub.3 CH.sub.3     CH.sub.3 78 7-NHSO.sub.2 C.sub.6 H.sub.4 -4-CH.sub.2 CH.sub.3 H CH.sub.3     79 7-NHSO.sub.2 C.sub.6 H.sub.11 H CH.sub.3 80 7-N(C.sub.6      H.sub.11)SO.sub.2 (CH.sub.2).sub.5      CH.sub.3 H CH.sub.3 81 7-Sn(CH.sub.3).sub.3 CH.sub.3 CH.sub.3 82     7-Sn(OCH.sub.2 CH.sub.3).sub.3 H CH.sub.3 83 7-Si(CH.sub.3).sub.2     C.sub.6 H.sub.5 H CH.sub.3 84 7-Si(OC.sub.4 H.sub.9 -n).sub.3 H CH.sub.3     85 7-Si[OCH.sub.2      C(CH.sub.3).sub.3 ].sub.3 H CH.sub.3

                                      TABLE 3                                     __________________________________________________________________________    PHTHALOCYANINE COMPOUNDS                                                      (Pc = PHTHALOCYANINE NUCLEUS)                                                 EX.                                                                           NO.                                                                              COMPOUND                                                                   __________________________________________________________________________    86 1(4), 8(11), 15(18), 22(25)-Tetra[4(2-ethylhexyloxycarbonyl)phenylthio]       PcH.sub.2                                                                  87 2(3), 9(10), 16(17), 23(24)-Tetraphenoxy-PcAl--OC.sub.6 H.sub.4               -4-CO.sub.2 CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 -n                 88 2(3), 9(10), 16(17), 23(24)-Tetraphenoxy-PcAl--SC.sub.6 H.sub.4               -2-CO.sub.2 (CH.sub.2).sub.3 CH(CH.sub.3).sub.2                            89 2(3), 9(10), 16(17), 23(24)-Tetraphenoxy-PcAl--S--C.sub.6 H.sub.4             -2-CO.sub.2 C.sub.4 H.sub.9 -n                                             90 2(3), 9(10), 16(17), 23(24)-Tetraphenoxy-PcAlOC.sub.6 H.sub.4 -4-C.sub.       6 H.sub.11                                                                 91 2(3), 9(10), 16(17), 23(24)-Tetra-(4-n-butoxyphenoxy)-PcAlOCOCF.sub.3      92 2(3), 9(10), 16(17), 23(24)-Tetra-(4-nonylphenoxy)PcH.sub.2                93 2(3), 9(10), 16(17), 23(24)-Tetra-(4-t-butylphenylthio)-PcH.sub.2          94 2(3), 9(10), 16(17), 23(24)-Tetra-(4-isoamylphenylthio)-PcZn               95 2(3), 9(10), 16(17), 23(24)-Tetra-(4-n-hexylphenoxy)-PcSiCl.sub.2          96 2(3), 9(10), 16(17), 23(24)-Tetra-[4-(2-ethylhexyloxycarbonyl)-phenylth       io]PcH.sub.2                                                               97 2(3), 9(10), 16(17), 23(24)-Tetra-(4-cyclohexylphenoxy)-PCSi(OCH.sub.2        CH.sub.2 OC.sub.4 H.sub.9 -n).sub.2                                        98 2(3), 9(10), 16(17), 23(24)-Tetra-(4-dodecylphenoxy)-PcSi(OC.sub.4            H.sub.9 -n).sub.2                                                          99 2(3), 9(10), 16(17), 23(24)-Tetra-(4-undecylphenoxy)-PcSi(OCOCH.sub.3).       sub.2                                                                      100                                                                              2(3), 9(10), 16(17), 23(24)-Tetra-(4-tetradecylphenoxy)-PcH.sub.2          101                                                                              2(3), 9(10), 16(17), 23(24)-Tetra-(4-octadecylphenoxy)-PcMg                102                                                                              2(3), 9(10), 16(17), 23(24)-Tetra-(dodecylthio)-PcH.sub.2                  103                                                                              2(3), 9(10), 16(17), 23(24)-Tetra-(4-carbodecyloxyphenoxy)-PcH.sub.2       104                                                                              2(3), 9(10), 16(17), 23(24)-Tetra-(2(carbononyloxyphenylthio)-PcSi(OH).       sub.2                                                                      105                                                                              2(3), 9(10), 16(17), 23(24)-Tetrallyloxy-PcAlCl                            106                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(2-ethylhexylamino)PcH.sub.2              107                                                                              2(3), 9(10), 16(17), 23(24)-Tetracyclohexyloxy-PcSi[OC(C.sub.6                H.sub.5).sub.3 ]1.sub.2                                                    108                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(6-t-butylbenzothiazol-2-ylthio)-PcAlC       l                                                                          109                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(6-isopropylbenzoxazol-2-ylthio)PcAlOC       OCF.sub.3                                                                  110                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(5-n-hexyl-1,3,4-thiadiazol-2-ylthio)P       cAlCl                                                                      111                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(4,6-di-methyl-2-pyridylthio)-PcSi(OC.       sub.6 H.sub.4 -4-t-butyl).sub.2                                            112                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(4-cyclohexylphenyl)telluro-PcSi(OH.su       b.2)                                                                       113                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(4-dodecylphenyl)seleno-PcAlCl            114                                                                              2(3), 9(10), 16(17), 23 (24)-Tetra-n-octylthio-PcSi(OC.sub.6 H.sub.4          -4-F).sub.2                                                                115                                                                              2(3), 9(10), 16(17), 23(24)-Tetra-(6-t-butyl-2-naphthylthio)-PcAlOH        116                                                                              2(3), 9(10), 16(17), 23(24)-Tetradioctylamino-PcAlOCOCF.sub.3              117                                                                              2(3), 9(10), 16(17), 23(24)-Tetrapiperidino-PcAlOH                         118                                                                              2(3), 9(10), 16(17), 23(24)-Tetratriazol-3-ylthio-PcSiCl.sub.2             119                                                                              2(3), 9(10), 16(17), 23(24)-Tetratriazol-3-ylthio-PcH.sub.2                120                                                                              2(3), 9(10), 16(17), 23(24)-Tetratriazol-3-ylthio-PcSi(OH.sub.)2           121                                                                              2(3), 9(10), 16(17), 23(24)-Tetra[(2-ethylhexyloxy)anilino]-PcH.sub.2      122                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(4-dodecyloxyphenoxy)-PcH.sub.2           123                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(2-naphthyloxy)-PcH.sub.2                 124                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(4-carboneopentyloxyphenylthio)-PcH.su       b.2                                                                        125                                                                              1,4,8,11,15,18,22,25-octahexyloxy-2,3,9,10,16,17,23,24-octachloro-PcSi(       OH).sub.2                                                                  126                                                                              1,4,8,11,15,18,22,25-octa-n-butoxy-2,3,9,10,16,17,23,24-octachloro-PcH.       sub.2                                                                      127                                                                              1,4,8,11,15,18,22,25-octa-isohexyloxy-2,3,9,10,16,17,23,24-octachloro-P       cH.sub.2                                                                   128                                                                              Hexadecamethyl-PcAlOH                                                      129                                                                              Hexadecaanilino-PcSi(OH).sub.2                                             130                                                                              Hexadeca(4-methylphenylthio)-PcSi(OC.sub.6 F.sub.5).sub.2                  131                                                                              1,4,8,11,15,18,22,25-Octabutoxy-PcH.sub.2                                  132                                                                              1, 4,8,11,15, 18,22, 25-Octaphenylthio-PcSi[  O--Si(CH.sub.3).sub.2           C.sub.6 H.sub.5 ].sub.2                                                    133                                                                              1,4,8,11,15,18,22,25-Octa-(4-n-hexyloxyphenoxy)-PcH.sub.2                  134                                                                              1,4,8,11,15,18,22,25-Octa-(4-t-butylphenylthio)-PcH.sub.2                  135                                                                              1,4,8,11,15,18,22,25-Octa-(4-octylthiophenylthio)PcSiCl.sub.2              136                                                                              2,3,9,10,16,17,23,24-Octaethoxy-Pc--Al--OH                                 137                                                                              2,3,9,10,16,17,23,24-Octa-(4-t-butylphenylthio)PcH.sub.2                   138                                                                              2,3,9,10,16,17,23,24-Octadecyloxy-Pc--SiCl.sub.2                           139                                                                              2,3,9,10,16,17,23,24-Octaphenylthio-PcSi(OC.sub.6 H.sub.5).sub.2           140                                                                              2,3,9,10,16,17,23,24-Octa(12-acetoxydodecyloxy)PcSi[OC.sub.6 H.sub.4          -4-CO.sub.2 hexyl].sub.2                                                   141                                                                              2,3,9,10,16,17,23,24-Octa(2-ethylhexyl)PcSi(OCOCF.sub.3).sub.2             142                                                                              2,3,9,10,16,17,23,24-Octa(2-isooctylphenylthio)-PcAlOH                     143                                                                              2,3,9,10,16,17,23,24-Octa(t-butoxyphenoxy)-PcAlCl                          144                                                                              2,3,9,10,16,17,23,24-Octa(6-isopropylbenzothiazol-2-ylthio)PcAlOH          145                                                                              1,4,8,11,15,18,22,25-Octa(3-methylbutoxy)-2,3,9,10,16,17,23,24-octaphen       ylthio-PcAlOH                                                              146                                                                              1,4,8,11,15,18,22,25-Octa(3-methylbutoxy)-2,3,9,10,16,17,23,24-octaphen       oxy-PcSi(OH).sub.2                                                         147                                                                              1,4,8,11,15,18,22,25-Octa(3-methylbutoxy)-2,3,9,10,16,17,23,24-octa-n-b       utylthio-PcAlOH                                                            148                                                                              1,4,8,11,15,18,22,25-Octa(3-methylbutoxy)-2,3,9,10,16,17,23,24-octa-4(t       -butylphenylthio)PcAlCl                                                    149                                                                              1,4,8,11,15,18,22,25-Octafluoro-2,3,9,10,16,17,23,24-octaphenylthio-PcA       lOC.sub.6 H.sub.4 -4-CO.sub.2 CH.sub.3                                     150                                                                              1,4,8,11,15,18,22,25-Octafluoro-2,3,9,10,16,17,23,24-octaphenylthio-PcA       lOH                                                                        151                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(N-cyclohexyl-N-decanylamino)-PcAlCl      152                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(3,5-di-t-butylphenoxy)PcH.sub.2          153                                                                              2(3), 9(10), 16(17), 23(24)-Tetracyclohexanesulfonamido-PcAlOH             154                                                                              2(3), 9(10), 16(17), 23(24)-Tetra[4-(carbo-2-ethylhexyloxy)phenoxy]PcH.       sub.2                                                                      155                                                                              2(3), 9(10), 16(17), 23 (24)-Tetra-[Si(CH.sub.3).sub.2 C.sub.6 H.sub.5        ]--PcAlCl                                                                  156                                                                              2(3), 9(10), 16(17), 23(24)-Tetra[Si(OCH.sub.3).sub.3 ]--PcAlOH            157                                                                              2(3), 9(10), 16(17), 23 (24)-Tetra[Sn(C.sub.4 H.sub. 9 -n).sub.3              --AlCl                                                                     158                                                                              2(3), 9(10), 16(17), 23(24)-Tetra[Sn(Oamyl).sub.3 ]--PcAlOH                159                                                                              2(3), 9(10), 16(17), 23(24)-Tetra[N-phenylbutanesulfonamido)-PcAlCl        160                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(N-octylbenzamido)-PcSi(OH).sub.2         161                                                                              2(3), 8(11), 15(18), 22(25)-Tetraamino-PcAlOH                              162                                                                              PcAlOC.sub.6 H.sub.4 -4-CH.sub.2 CH.sub.2 OCOCH.sub.2 CH(C.sub.2              H.sub.5)C.sub.4 H.sub.9 -n                                                 163                                                                              PcAlOC.sub.6 H.sub.2 -3,5-di-CO.sub.2 octyl-4-NO.sub.2                     164                                                                              1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-Hexadecyl(4-t-butylphenylthio       )PcH.sub.2                                                                 165                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(3-pentadecylphenoxy)-PcH.sub.2           166                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(l,l-dimethylpropyl)-PcH.sub.2            167                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(l,l-dimethylpropyl)-PcAlOC.sub.6            H.sub.3 -3,5-di-CO.sub.2 cyclohexyl                                        168                                                                              2(3), 9(10), 16(17), 23(24)-Tetra(n-dodecylthio)-PcAlOC.sub.6 H.sub.3         -3,5-di-CO.sub.2 -methyl                                                   169                                                                              1(4), 8(11), 15(18), 22(25)-Tetra-NHC.sub.8 H.sub.17 --PcH.sub.2           170                                                                              1(4), 8(11), 15(18), 22(25)-Tetra-NHC.sub.12 H.sub.25 --PcH.sub.2          171                                                                              1(4), 8(11), 15(18), 22(25)-Tetra-[N(COCF.sub.3)C.sub.8 H.sub.17              ]--PcAlCl                                                                  172                                                                              1(4), 8(11), 15(18), 22(25)-Tetra-N(C.sub.8 H.sub.17).sub.2 --PcAlCl       __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________    NAPHTRALOCYANINE COMPOUNDS                                                    (Nc = NAPHTHALOCYANINE NUCLEUS)                                               EX. NO.                                                                            COMPOUND                                                                 __________________________________________________________________________    173  2(3), 11(12), 20(21), 29(30)-Tetra-t-butyl-NcH.sub.2                     174  2(3), 11(12), 20(21), 29(30)-Tetraisopentyl-NcAlOC.sub.6 H.sub.4              -4-CO.sub.2 CH.sub.3                                                     175  2(3), 11(12), 20(21), 29(30)-Tetraisobutyl-NcSi(OH).sub.2                176  2(3), 11(12), 20(21), 29(30)-Tetraisoamyl-NcAlOH                         177  2(3), 11(12), 20(21), 29(30)-Tetraoctyl-NcH.sub.2                        178  2(3), 11(12), 20(21), 29(30)-Tetraisohexyl-NcSi[OSn(C.sub.4 H.sub.9           n).sub.3 ].sub.2                                                         179  2(3), 11(12), 20(21), 29(30)-Tetraoctyl-NcSi[OGe[Ohexyl].sub.3                ].sub.2                                                                  180  2(3), 11(12), 20(21), 29(30)-Tetranonyl-NcSi(OCH.sub.2 CH.sub.2               CH.sub.2 CH.sub.2 OC.sub.4 H.sub.9 n).sub.2                              181  2(3), 11(12), 20(21), 29(30)-Tetra-(2,2,4-trimethylpentyl)-NcAlOC.sub         .6 H.sub.4 -4-                                                                CO.sub.2 methyl                                                          182  2(3), 11(12), 20(21), 29(30)-Tetra-(2-ethylhexyl)-NcAlOC.sub.6                H.sub.3 -3,5-                                                                 diCO.sub.2 dodecyl                                                       183  2(3), 11(12), 20(21), 29(30)-Tetra-t-butyl-NcSi(OC.sub.6 H.sub.4              -4-CO.sub.2 cyclohexyl).sub.2                                            184  2(3), 11(12), 20(21), 29(30)-Tetra-t-butyl-NcSi(OCO-t-butyl).sub.2       185  2(3), 11(12), 20(21), 29(30)-TetrapentadecylNcH.sub.2                    186  2(3), 11(12), 20(21), 29(30)-Tetra(hexadecyloxy)-NcH.sub.2               187  2(3), 11(12), 20(21), 29(30)-Tetra-t-butyl-NcZn                          188  2(3), 11(12), 20(21), 29(30)-Tetrabenzyl-NcAlOH                          189  2(3), 11(12), 20(21), 29(30)-Tetra(2-ethylhexyloxy)-NcAlCl               190  NcSi(OCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 OC.sub.4 H.sub.9 n).sub.2      191  NcSiOCO(CH.sub.2).sub.7 CH.sub.3                                         192                                                                                 ##STR40##                                                               193  2(3), 11(12), 20(21), 29(30)-Tetra-[OC.sub.6 H.sub.4 CO.sub.2                 (CH.sub.2).sub.2 CH.sub.3 ]NcAlCl                                        194  2(3), 11(12), 20(21), 29(30)-Tetra-[OC.sub.6 H.sub.3 -3,5-diCO.sub.2          CH.sub.2 CH(CH.sub.3).sub.2 ]NcAlOH                                      195  2(3), 11(12), 20(21), 29(30)-Tetra[SC.sub.6 H.sub.4 -3-CO.sub.2               CH.sub.2 CH(CH.sub.3).sub.2 ]NcSi(OH).sub.2                              196  2(3), 11(12), 20(21), 29(30)-Tetra-n-butoxy-NcSi[OSi(C.sub.6                  H.sub.5).sub.3 ].sub.2                                                   197  2(3), 11(12), 20(21), 29(30)-Tetra-n-butoxy-NcSi[OCOC.sub.6 H.sub.11)         .sub.2                                                                   198  2(3), 11(12), 20(21), 29(30)-Tetradodecyloxy-NcSi(OH).sub.2              199  2(3), 11(12), 20(21), 29(30)-Tetra(6-dodecyloxybenzothiazol-2-ylthio)         -NcAlOH                                                                  200  2(3), 11(12), 20(21), 29(30)-Tetra(6-hexylbenzimidazol-2-ylthio)-NcAl         OCOCF.sub.3                                                              201  2(3), 11(12), 20(21), 29(30)-Tetra(t-butylphenylseleno)-NcAlCl.sub.2     202  2(3), 11(12), 20(21), 29(30)-Tetra(n-butylphenyltelluro)-NcSiCl.sub.2    203  2(3), 11(12), 20(21), 29(30)-Tetra(t-butylanilino)-NcSi(OH).sub.2        204  2(3), 11(12), 20(21), 29(30)-Tetra(6-n-butyl-2-naphthyloxy)-NcSi(OCOC         F.sub.3).sub.2                                                           205  2(3), 11(12), 20(21), 29(30)-Tetra(6-neopentyl-2-naphthylthio)-NcSi(O         COCH.sub.3).sub.2                                                        206  2(3), 11(12), 20(21), 29(30)-Tetraallyloxy-NcAlOH                        207  2(3), 11(12), 20(21), 29(30)-Tetrapropargyloxy-NCSi(OH).sub.2            208  2(3), 11(12), 20(21), 29(30)-Tetra(cyclohexyloxy)-NCSi[OC.sub.6               H.sub.3 -3,5-diCO.sub.2 CH.sub.3 ].sub.2                                 209  2(3), 11(12), 20(21), 29(30)-Tetra(2-phenoxyethoxy)-NcAlOH               210  2(3), 11(12), 20(21), 29(30)-Tetra(2-phenylethoxy)-NcH.sub.2             211  2(3), 11(12), 20(21), 29(30)-Tetra(benzyloxy)-Nc AlOH                    212  2(3), 11(12), 20(21), 29(30)-Tetrapiperidino-NcSi(OH).sub.2              213  5,9,14,18,23,27,32,36-Octa(N-n-butyl-N-phenylamino)-NcSi(OH).sub.2       214  5,9,14,18,23,27,32,36-Octa(di-N,N-n-butylamino)-NcAlCl                   215  5,9,14,18,23,27,32,36-Octa-n-butoxy-NcSi(OCCOCF.sub.3).sub.2             216  5,9,14,18,23,27,32,36-Octa-n-butoxy-NcSi(OH).sub.2                       217  5,9,14,18,23,27,32,36-Octaphenoxy-NcH.sub.2                              218  5,9,14,18,23,27,32,36-Octaallyloxy-NcAlOC.sub.6 H.sub.4 -4-CO.sub.2           menthyl                                                                  219  5,9,14,18,23,27,32,36-Octa(octylthio)-NcAlCl                             220  2(3), 11(12), 20(21), 29(30)-Tetra(4-t-butylphenoxy)-NcAlOH              221  2(3), 11(12), 20(21), 29(30)-Tetra(4-isoamylphenoxy)-NcAlCl              222  2,3,11,12,20,21,29,30-Octa(4-cyclohexylphenoxy)-NcSi(OH).sub.2           223  2,3,11,12,20,21,29,30-Octa(hexadecyloxy)-NcAlOH                          224  2,3,11,12,20,21,29,30-Octa(octadecyloxy)-NcSi(OH).sub.2                  225  2,3,11,12,20,21,29,30-Octa(icosanyloxy)-NcSi(OCOCF.sub.3).sub.2          226  2,3,11,12,20,21,29,30-Octa(2-ethylhexyloxy)-NcAlCl                       227  2,3,11,12,20,21,29,30-Octa(undecanyloxy)-NcAlOH                          228  2,3,11,12,20,21,29,30-Octa(4-t-butoxyphenoxy)NcAlOH                      229  2,3,11,12,20,21,29,30-Octa(4-n-butoxyphenylthio)NcSi(OH).sub.2           230  2,3,11,12,20,21,29,30-Octa(2-ethylhexoxy)-NcSi(OH).sub.2                 231  2,3,11,12,20,21,29,30-Octa[CH.sub.3 O(CH.sub.2 CH.sub.2 O).sub.3              ]NcAlCl                                                                  232  2,3,11,12,20,21,29,30-Octa[OCH.sub.2 CH.sub.2 OCOCH.sub.2 CH(C.sub.2          H.sub.5)C.sub.4 H.sub.9 n]NcSi(OH).sub.2                                 233  2,3,11,12,20,21,29,30-Octa(4-t-butoxybutylthio)-NcAlOH                   234  2,3,11,12,20,21,29,30-Octamethyl-NcAlOH                                  235  2,3,11,12,20,21,29,30-Octa-(4-t-butylphenylthio)-NcSi(OH).sub.2          236  2(3), 11(12), 20(21), 29(30)-Tetradiethylamino-NcAlOH                    237  2(3), 11(12), 20(21), 29(30)-Tetramorpholino-NcAlOCOCF.sub.3             238  2(3), 11(12), 20(21), 29(30)-Tetra-O(C.sub.2 H.sub.4 O).sub.2                 CH.sub.3 NcSiCl.sub.2                                                    239  2(3), 11(12), 20(21), 29(30)-Tetra-O(C.sub.2 H.sub.4 O).sub.3                 CH.sub.3 NcSi(OH).sub.2                                                  240  2(3), 11(12), 20(21), 29(30)-Tetra[(CH.sub.3).sub.3 SiCH.sub.2                S]NcSi[OSi(C.sub.4 H.sub.9).sub.3 ].sub.2                                241  2(3), 11(12), 20(21), 29(30)-Tetra[(C.sub.2 H.sub.5).sub.3 Si(CH.sub.         2).sub.2 S]NcSi[OSi(CH.sub.3).sub.3 ].sub.2                              242  2(3), 11(12), 20(21), 29(30)-Tetra[(C.sub.6 H.sub.11).sub.3 SiCH.sub.         2 S]NcSi[OSi(OCH.sub.3).sub.3 ].sub.2                                    243  2(3), 11(12), 20(21), 29(30)-Tetra[(CH.sub.3 O).sub.3 Si(CH.sub.2).su         b.3 S]NcGe[OSi(C.sub.2 H.sub.5).sub.3 ].sub.2                            244  2(3), 11(12), 20(21), 29(30)-Tetra[(C.sub.6 H.sub.5 O).sub.3                  SiCH.sub.2 S]NcGe[OSi(OCH.sub.3).sub.3 ].sub.2                           245  2(3), 11(12), 20(21), 29(30)-Tetra[(CH.sub.3).sub.3 SiCH.sub.2                CH.sub.2 O]NcSi(OH).sub.2 ]                                              246  2(3), 11(12), 20(21), 29(30)-Tetra[(CH.sub.3).sub.3 SiC(Cl).sub.2             CH.sub.2 S]NcSi[OSi(CH.sub.3).sub.3 ].sub.2                              247  2(3), 11(12), 20(21), 29(30)-Tetra[(C.sub.6 H.sub.5).sub.3 SiCH.sub.2          O]NcAlOH                                                                248  2(3), 11(12), 20(21), 29(30)-Tetra[(CH.sub.3).sub.3 SiCH.sub.2                S]NcSi[OSi(C.sub.2 H.sub.5).sub.3 ].sub.2                                249  2(3), 11(12), 20(21), 29(30)-Tetra[(CH.sub.3).sub.3 SiCH.sub.2                S]NcSi[OC.sub.18 H.sub.37).sub.2                                         250  2(3), 11(12), 20(21), 29(30)-Tetra[(CH.sub.3).sub.2 C.sub.6 H.sub.5           Si(CH.sub.2).sub.4 O]NcAlOH                                              251  2,3,11,12,20,21,29,30-Octa[(CH.sub.3).sub.3 SiCH.sub.2 S]NcSi(OH).sub         .2                                                                       252  5(36), 9(14), 18(23), 27(32)-Tetra(4-t-butylphenyl)-2(3),11(12),20(21         ),                                                                            29(30)-tetra-t-butyl-NcH.sub.2                                           253  5(36), 9(14), 18(23), 27(32)-Tetra(4-hexylphenyl)-NcH.sub.2              254  5(36), 9(14), 18(23), 27(32)-Tetra(4-octylphenyl)-NcH.sub.2              255  5(36), 9(14), 18(23), 27(32)-Tetra(4-dodecylohexyl)-NcAlOH               256  1(4), 10(13), 19(22), 28(31)-Tetra(dodecylamino)-NcAlCl                  257  1(4), 10(13), 19(22), 28(31)-Tetra(n-octylamino)-NcAlOH                  258  1(4), 10(13), 19(22), 28(31)-Tetra(n-octylamino)-NcAlOC.sub.6                 H.sub.3 -3,5-di-CO.sub.2 CH.sub.3                                        259  2(3), 11(12), 20(21), 29(30)-Tetra(dodecylthio)-NcAlOH                   260  2(3), 11(12), 20(21), 29(30)-Tetra(n-octylthio)-NcAlCl                   261  2(3), 11(12), 20(21), 29(30)-Tetra(dodecylthio)-NcAlOC.sub.6 H.sub.3          -3,5-di-CO.sub.2 CH.sub.3                                                262  2,3,11,12,20,21,29,30-Octa(dodecylthio)NcSi(OH).sub.2                    263  2,3,11,12,20,21,29,30-Octa(dodecylthio)NcSi(OC.sub.6 H.sub.4                  -4-CO.sub.2 CH.sub.3).sub.2                                              264  NcSi(OCOC.sub.6 H.sub.4 -4-t-butyl).sub.2                                265  NcSi[OCOC.sub.6 H.sub.4 -4-CO.sub.2 (CH.sub.2).sub.12 CH.sub.3                ].sub.2                                                                  266  NcSi[COCONHC.sub.6 H.sub.4 -4-CO.sub.2 (CH.sub.2 CH.sub.2 O).sub.3            CH.sub.3 ].sub.2                                                         267  NcSi[OCONHC.sub.6 H.sub.3 -3,5-di-CO.sub.2 CH.sub.2 CH(C.sub.2                H.sub.5)C.sub.4 H.sub.9 -n].sub.2                                        268  2(3), 11(12), 20(21), 29(30)-Tetra-t-butyl-NcMg                          269  NcSi[OC.sub.6 H.sub.3 -3,5-diCO.sub.2 CH.sub.2 CH(C.sub.2 H.sub.5)C.s         ub.4 H.sub.9 -n].sub.2                                                   270  NcAlOC.sub.6 H.sub.4 -4-OC.sub.10 H.sub.21                               271  2(3), 11(12), 20(21), 29(30)-Tetra(2-ethylhexylamino)NcH.sub.2           272  2(3), 11(12), 20(21), 29(30)-Tetra(4-t-butylphenoxy)NcZn                 273  2(3), 11(12), 20(21), 29(30)-Tetra(4-n-hexylphenylthio)NcMg              274  2(3), 11(12), 20(21), 29(30)-Tetra[4-CHNCH.sub.2 (C.sub.2 H.sub.5)C.s         ub.4 H.sub.9 n-phenoxy]NcH.sub.2                                         275  NcSi[OC.sub.6 H.sub.4 -4-CHNC.sub.6 H.sub.4 -4-CO.sub.2 CH.sub.2              CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 -n].sub.2                             __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________    CROCONIC ACID DERIVED COMPOUNDS                                                ##STR41##                                                                    EX. NO.                                                                            R.sub.1, R.sub.2   R.sub.3, R.sub.4                                                                    R', R"                                          __________________________________________________________________________    276  7-CO.sub.2 (CH.sub.2).sub.3 CH.sub.3                                                             H     CH.sub.3                                        277  7-CO.sub.2 CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3 CH.sub.3                                 H     CH.sub.3                                        278  7-CO.sub.2 NHC.sub.8 H.sub.17                                                                    H     CH.sub.3                                        279  7-CO.sub.2 NHC.sub.6 H.sub.4 -4-C(CH.sub.3).sub.3                                                CH.sub.3                                                                            CH.sub.3                                        280  7-SO.sub.2 NHC.sub.12 H.sub.25                                                                   C.sub.6 H.sub.5                                                                     CH.sub.3                                        281  7-(CH.sub.2).sub.7 CH.sub.3                                                                      CH.sub.2 CH.sub.3                                                                   CH.sub.3                                        282  7-CO.sub.2 C.sub.6 H.sub.10 -4-CH.sub.3                                                          CH.sub.3                                                                            CH.sub.3, CH.sub.2 CH.sub.3                     283  7-SO.sub.2 (CH.sub.2).sub.3 CH(CH.sub.3)CH.sub.3                                                 H     CH.sub.3, CH(CH.sub.3).sub.2                    284  7-CO.sub.2 C.sub.6 H.sub.4 -4-O(CH.sub.2).sub.12 CH.sub.3                                        H     CH.sub.3, CH.sub.2 CH(CH.sub.3).sub.2           285  7-CO.sub.2 NHC.sub.6 H.sub.4 -4-C.sub.6 H.sub.11                                                 H     CH.sub.3                                        286  7-SO.sub.2 NHCH.sub.2 (CH.sub.2 CH.sub.3)C.sub.6 H.sub.9 n                                       H     CH.sub.3                                        287  7-SO.sub.2 N(C.sub.4 H.sub.9 n)C.sub.6 H.sub.11                                                  H     CH.sub.3                                        288  7-S(CH.sub.2).sub.10 CH.sub.3                                                                    H     CH.sub.3                                        289  7-OCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 n                                                 H     CH.sub.3                                        290  8-(CH.sub.2).sub.3 CH.sub.3                                                                      H     CH.sub.3                                        __________________________________________________________________________

We claim:
 1. A method for tagging a petroleum hydrocarbon foridentification purposes, which comprises dissolving at ambienttemperature in said hydrocarbon a near infrared fluorophoric compoundselected from the group consisting of squaraines phthalocyanines andnaphthalocyanines having at least one straight or branched chain C₄ toC₂₀ alkyl group, and croconic acid derivatives.
 2. The method of claim1, wherein the petroleum hydrocarbon is gasoline.
 3. The method of claim1, wherein the petroleum hydrocarbon is kerosene.
 4. The method of claim1, wherein the petroleum hydrocarbon is lubricant oil.
 5. The method ofclaim 1, wherein the petroleum hydrocarbon is furnace oil.
 6. The methodof claim 1, wherein the near infrared fluorophoric compound is selectedfrom the group consisting of phthalocyanines, 2,3-naphthalocyanines,squaraines and croconic acid derivatives and correspond to Formulae I,II, III, and IV, respectively: ##STR42## wherein Pc and Nc represent thephthalocyanine and naphthalocyanine moieties of Formulae Ia and IIa,##STR43## respectively, covalently bonded to hydrogen or to halometals,organometallic groups, and oxymetals selected from the group consistingof AlCl, AlBr, AlF, AlOR₅, AlSR₅, SICl₂, SiF₂, Si(OR₆)₂, Si(SR₆)₂, Znand Mg, wherein R₅ and R₆ are selected from hydrogen, alkyl, aryl,heteroaryl, alkanoyl, arylcarbonyl, arylaminocarbonyl, trifluoroacetyl,##STR44## wherein R₇, R₈ and R₉ are independently selected from alkyl,phenyl or phenyl substituted with alkyl, alkoxy or halogen;X is selectedfrom oxygen, sulfur, selenium, tellurium or a group of the formulaN--R₁₀, wherein R₁₀ is hydrogen, cycloalkyl, alkyl, acyl, alkylsulfonyl,or aryl or R₁₀ and R taken together form an aliphatic or aromatic ringwith the nitrogen atom to which they are attached; Y is selected fromalkyl, aryl, heteroaryl, halogen or hydrogen; R is selected fromhydrogen, unsubstituted or substituted alkyl, alkenyl, alkynyl, C₃ -C₈cycloalkyl, aryl, heteroaryl, alkylene ##STR45## or alkylene ##STR46##--(X-R)_(m) is one or more groups selected from alkylsulfonylamino,arylsulfonylamino, or a group selected from the formulae --X(C₂ H₄O)_(z) R, ##STR47## wherein R is as defined above; Z is an integer offrom 1-4; or two --(X-R)_(m) groups can be taken together to formdivalent substituents of the formula ##STR48## wherein each X₁ isindependently selected from --O--, --S--, or --N--R₁₀ and A is selectedfrom ethylene; propylene; trimethylene; and such groups substituted withlower alkyl, lower alkoxy, aryl and cycloalkyl; 1,2-phenylene and1,2-phenylene containing 1-3 substituents selected from lower aklyl,lower alkoxy or halogen; R' and R" are independently selected from loweralkyl and cycloalkyl; R₁ and R₂ are independently selected fromhydrogen, alkyl, alkoxy, halogen, aryloxy, alkylthio, arylthio,alkylsulfonyl, arylsulfonyl, alkyl-sulfonylamino, arylsulfonylamino,cycloalkylsulfonylamino, unsubstituted and substituted carbamoyl andsulfamyl, alkoxycarbonyl, cycloalkoxycarbonyl, alkanoyloxy, ##STR49## R₃and R₄ are independently selected from hydrogen, lower alkyl, alkenyl oraryl; n is an integer from 0-16; n₁ is an integer from 0-24, m is aninteger from 0-16; and m₁ is an integer from 0-24; provided that thesums of n+m and n₁ +m₁ are 16 and 24, respectively.
 7. The method ofclaim 6, wherein the near infrared fluorescing compound is a squarainecompound of Formula III, and wherein R₁ and R₂ are independentlyalkoxycarbonyl.
 8. The method of claim 6, wherein the near infraredfluorescing compound is a 2,3-naphthalocyanine compound of Formula II,and wherein the naphthalocyanine moiety is bonded to hydrogen, AlCl,AlOH, AlOR₅, SICl₂, Si(OH)₂, Si(OR₆)₂, Zn or Mg, m₁ is 0, Y is alkyl andn₁ is 24 and wherein the Y groups represent at least four alkyl or arylgroups.
 9. The method of claim 6, wherein the naphthalocyanine compoundof Formula II is bonded to hydrogen.
 10. The method of claim 6, whereinthe near infrared fluorescing compound is a phthalocyanine compound ofFormula I, and wherein X is oxygen, R is aryl or alkyl, Y is hydrogen, mis 4, and n is 12; and wherein the phthalocyanine moiety is bonded tohydrogen, AlCl, AlOH, AlOCOCF₃, AlOR₅, SICl₂, Si(OH)₂, Si(OR₆)₂, Zn orMg.
 11. The method of claim 6, wherein the phthalocyanine compound ofFormula I is bonded to hydrogen.
 12. A method for identifying apetroleum hydrocarbon, wherein said product has one or more nearinfrared fluorophoric compounds dissolved therein, which comprises thesteps:(a) exposure of a petroleum hydrocarbon composition toelectromagnetic radiation having wavelengths of 670-850 nm, wherein saidpetroleum hydrocarbon composition comprises a petroleum hydrocarbonmaterial having dissolved therein one or more near infrared fluorescenttagging compounds selected from the group consisting of squaraines,phthalocyanines and naphthalocyanines having at least one straight orbranched chain C₄ to C₂₀ alkyl group and croconic acid derivatives,wherein said tagging compound(s) is (are) present in a concentrationsufficient to impart detectable fluorescence when exposed toelectromagnetic radiation of about 670-850 nm provided by light sources;followed by (b) detection of the emitted fluorescent radiation by nearinfrared detection means.
 13. The method of claim 12, wherein thepetroleum hydrocarbon material is gasoline.
 14. The method of claim 12,wherein the petroleum hydrocarbon material is kerosene.
 15. The methodof claim 12, wherein the petroleum hydrocarbon material is lubricantoil.
 16. The method of claim 12, wherein the petroleum hydrocarbonmaterial is furnace oil.
 17. The method of claim 12, wherein the nearinfrared fluorophoric compound is selected from the group consisting ofphthalocyanines, 2,3-naphthalocyanines, squaraines and croconic acidderivatives and correspond to Formulae I, II, III, and IV, respectively:##STR50## wherein Pc and Nc represent the phthalocyanine andnaphthalocyanine moieties of Formulae Ia and IIa, ##STR51##respectively, covalently bonded to hydrogen or to halometals,organometallic groups, and oxymetals selected from the group consistingof AlCl, AlBr, AlF, AlOR₅, AlSR₅, SiCl₂, SiF₂, Si(OR₆)₂, Si(SR₆)₂, Znand Mg, wherein R₅ and R₆ are selected from hydrogen, alkyl, aryl,heteroaryl, alkanoyl, arylcarbonyl, arylaminocarbonyl, trifluoroacetyl,##STR52## groups of the formulae ##STR53## wherein R₇, R₈ and R₉ areindependently selected from alkyl, phenyl or phenyl substituted withalkyl, alkoxy or halogen;X is selected from oxygen, sulfur, selenium,tellurium or a group of the formula N-R₁₀, wherein R₁₀ is hydrogen,cycloalkyl, alkyl, acyl, alkylsulfonyl, or aryl or R₁₀ and R takentogether form an aliphatic or aromatic ring with the nitrogen atom towhich they are attached; Y is selected from alkyl, aryl, heteroaryl,halogen or hydrogen; R is selected from hydrogen, unsubstituted orsubstituted alkyl, alkenyl, alkynyl, C₃ -C₈ cycloalkyl, aryl,heteroaryl, alkylene ##STR54## --(X-R)_(m) is one or more groupsselected from alkylsulfonylamino, arylsulfonylamino, or a group selectedfrom the formulae --X(C₂ H₄ O)_(z) R, ##STR55## wherein R is as definedabove; Z is an integer of from 1-4; or two --(X-R)_(m) groups can betaken together to form divalent substituents of the formula ##STR56##wherein each X₁ is independently selected from --O--, --S--, or --N-R₁₀and A is selected from ethylene; propylene; trimethylene; and suchgroups substituted with lower alkyl, lower alkoxy, aryl and cycloalkyl;1,2-phenylene and 1,2-phenylene containing 1-3 substituents selectedfrom lower aklyl, lower alkoxy or halogen; R' and R" are independentlyselected from lower alkyl and cycloalkyl; R₁ and R₂ are independentlyselected from hydrogen, alkyl, alkoxy, halogen, aryloxy, alkylthio,arylthio, alkylsulfonyl, arylsulfonyl, alkyl-sulfonylamino,arylsulfonylamino, cycloalkylsulfonylamino, unsubstituted andsubstituted carbamoyl and sulfamyl, alkoxycarbonyl, cycloalkoxycarbonyl,alkanoyloxy, ##STR57## R₃ and R₄ are independently selected fromhydrogen, lower alkyl, alkenyl or aryl; n is an integer from 0-16; n₁ isan integer from 0-24, m is an integer from 0-16; m₁ is an integer from0-24; provided that the sums of n+m and n₁ +m₁ are 16 and 24,respectively.
 18. The method of claim 17, wherein the near infraredfluorescing compound is a squaraine compound of Formula III, and whereinR₁ and R₂ are independently alkoxycarbonyl.
 19. The method of claim 17,wherein the near infrared fluorescing compound is a 2,3-naphthalocyaninecompound of Formula II, and wherein the naphthalocyanine moiety isbonded to hydrogen, AlCl, AlOH, AlOR₅, SiCl₂, Si(OH)₂, Si(OR₆)₂, Zn orMg, m₁ is 0, Y is alkyl and n₁ is 24 and wherein the Y groups representat least four alkyl or aryl groups.
 20. The method of claim 17, whereinthe naphthalocyanine compound of Formula II is bonded to hydrogen. 21.The method of claim 17, wherein the near infrared fluorescing compoundis a phthalocyanine compound of Formula I, and wherein X is oxygen, R isaryl or alkyl, Y is hydrogen, m is 4, and n is 12; and wherein thephthalocyanine moiety is bonded to hydrogen, AlCl, AlOH, AlOCOCF₃,AlOR₅, SiCl₂, Si(OH)₂, Si(OR₆)₂, Zn or Mg.
 22. The method of claim 17,wherein the phthalocyanine compound of Formula I is bonded to hydrogen.23. A petroleum hydrocarbon having dissolved therein at least one nearinfrared fluorophoric compound selected from the group consisting ofsquaraines, phthalocyanines and naphthalocyanines having at least onestraight or branched chain C₄ to C₂₀ alkyl group, and croconic acidderivatives.
 24. The petroleum hydrocarbon of claim 23, wherein the nearinfrared fluorophoric compound is selected from the group consisting ofphthalocyanines, 2,3-naphthalocyanines squaraines (squaric acidderivatives) and croconic acid derivatives and correspond to Formulae I,II, III, and IV, respectively: ##STR58## wherein Pc and Nc represent thephthalocyanine and naphthalocyanine moieties of Formulae Ia and IIa,##STR59## respectively, covalently bonded to hydrogen or to halometals,organometallic groups, and oxymetals selected from the group consistingof AlCl, AlBr, AlF, AlOR₅, AlSR₅, SiCl₂, SiF₂, Si(OR₆)₂, Si(SR₆)₂, Znand Mg, wherein R₅ and R₆ are selected from hydrogen, alkyl, aryl,heteroaryl, alkanoyl, arylcarbonyl, arylaminocarbonyl, trifluoroacetyl,##STR60## groups of the formulae ##STR61## wherein R₇, R₈ and R₉ areindependently selected from alkyl, phenyl or phenyl substituted withalkyl, alkoxy or halogen;X is selected from oxygen, sulfur, selenium,tellurium or a group of the formula N-R₁₀, wherein R₁₀ is hydrogen,cycloalkyl, alkyl, acyl, alkylsulfonyl, or aryl or R₁₀ and R takentogether form an aliphatic or aromatic ring with the nitrogen atom towhich they are attached; Y is selected from alkyl, aryl, heteroaryl,halogen or hydrogen; R is selected from hydrogen, unsubstituted orsubstituted alkyl, alkenyl, alkynyl, C₃ -C₈ cycloalkyl, aryl,heteroaryl, alkylene ##STR62## --(X-R)_(m) is one or more groupsselected from alkylsulfonylamino, arylsulfonylamino, or a group selectedfrom the formulae --X(C₂ H₄ O)_(z) R, ##STR63## wherein R is as definedabove; Z is an integer of from 1-4; or two --(X-R)_(m) groups can betaken together to form divalent substituents of the formula ##STR64##wherein each X₁ is independently selected from --O--, --S--, or --N-R₁₀and A is selected from ethylene; propylene; trimethylene; and suchgroups substituted with lower alkyl, lower alkoxy, aryl and cycloalkyl;1,2-phenylene and 1,2-phenylene containing 1-3 substituents selectedfrom lower aklyl, lower alkoxy or halogen; R' and R" are independentlyselected from lower alkyl and cycloalkyl; R₁ and R₂ are independentlyselected from hydrogen, alkyl, alkoxy, halogen, aryloxy, alkylthio,arylthio, alkylsulfonyl, arylsulfonyl, alkylsulfonylamino,arylsulfonylamino, cycloalkylsulfonylamino, unsubstituted andsubstituted carbamoyl and sulfamyl, alkoxycarbonyl, cycloalkoxycarbonyl,alkanoyloxy, ##STR65## R₃ and R₄ are independently selected fromhydrogen, lower alkyl, alkenyl or aryl; n is an integer from 0-16; n₁ isan integer from 0-24, m is an integer from 0-16; m₁ is an integer from0-24; provided that the sums of n+m and n₁ +m₁ are 16 and 24,respectively.
 25. The petroleum hydrocarbon of claim 23, wherein thenear infrared fluorescing compound is a squaraine compound of FormulaIII, and wherein R₁ and R₂ are independently alkoxycarbonyl.
 26. Thepetroleum hydrocarbon of claim 23, wherein the near infrared fluorescingcompound is a 2,3-naphthalo-cyanine compound of Formula II, and whereinthe naphthalocyanine moiety is bonded to hydrogen, AlCl, AlOH, AlOR₅,SiCl₂, Si(OH)₂, Si(OR₆)₂, Zn or Mg, m₁ is 0, Y is alkyl and n₁ is 24 andwherein the Y groups represent at least four alkyl or aryl groups. 27.The petroleum hydrocarbon of claim 24, wherein the naphthalocyaninecompound of Formula II is bonded to hydrogen.
 28. The petroleumhydrocarbon of claim 24, wherein the near infrared fluorescing compoundis a phthalocyanine compound of Formula I, and wherein X is oxygen, R isaryl or alkyl, Y is hydrogen, m is 4, and n is 12; and wherein thephthalocyanine moiety is bonded to hydrogen, AlCl, AlOH, AlOCOCF₃,AlOR₅, SiCl₂, Si(OH)₂, Si(OR₆)₂, Zn or Mg.
 29. The petroleum hydrocarbonof claim 24, wherein the phthalocyanine compound of Formula I is bondedto hydrogen.
 30. The petroleum hydrocarbon of claim 24, wherein the nearinfrared fluorescing compound is selected from the group consisting of1(4) , 8(11) , 15(18) ,22(25)-tetra[4(2-ethylhexyloxycarbonyl)phenylthio]PcH₂ ; 2(3), 9(10),16(17), 23(24)-Tetra-(4-nonylphenoxy)PcH₂ ; 2(3), 9(10), 16(17),23(24)-Tetra-(4-isoamylphenylthio)-PcZn; 2(3), 9(10), 16(17),23(24)-tetra(2-ethylhexylamino)PcH₂ ; 2(3), 9(10), 16(17),23(24)-tetra(3,5-di-t-butylphenoxy)PcH₂ ; 2(3), 9(10), 16(17),23(24)-tetra[4-(carbo-2-ethylhexyloxy)phenoxy]PcH₂ ; 2(3), 9(10),16(17), 23(24)-tetra (3-pentadecylphenoxy)-PcH₂ ; 2(3), 11(12), 20(21),29(30)-tetra-t-butyl-NcH₂ ; 2(3), 11(12), 20(21), 29(30)-tetraactyl-NcH₂; and 2(3), 11(12), 20(21), 29(30)-tetra-t-butyl-NcZn; 1, 4, 8, 11, 15,18, 22, 25-octabutoxy-PcH₂ ; 2(3), 9(10), 16(17),23(24)-tetra(phenylthio)pcH₂ ; 2(3), 9(10), 16(17),23(24)-tetra(4-t-butylphenylthio)pcH₂ ; 5, 9, 14, 18, 23, 27, 32,36-octabutoxy-NcH₂ ; 5(36), 14(9), 23(18),32(27)-tetra(4-t-butylphenyl)-3(2), 12(11), 21(20),30(29)-tetra-t-butyl-NcH₂ ; 5(36), 14(9), 23(18),32(27)-tetra-[4-(2-ethylhexylamino)phenyl]-3(2), 12(11), 21(20),30(29)-tetra-(2-ethylhexylamino)NcH₂ ; wherein Pc is a phthalocyaninemoiety and Nc is a naphthalocyanine moiety.
 31. The petroleumhydrocarbon of claim 24 wherein the near infrared fluorescing compoundis 2(3), 11(12), 20(21), 29(30)-tetra-t-butyl-NcH₂, wherein Nc is anaphthalocyanine moiety.
 32. The petroleum hydrocarbon of claim 23,wherein the near infrared flurophoric compound is non-metallated.